Method for manufacturing a container containing a liquid

Abstract

To provide a method for manufacturing liquid-filled containers that can prevent damaged liquid-filled containers from being formed in liquid blow molding.SOLUTION: A method for manufacturing a liquid-filled container C containing a liquid content from a preform 2 includes a stretching step in which the synthetic resin-made preform 2 placed in a mold 10 is stretched axially by a stretching rod 23, and the bottom 2c of the preform 2, which moves downward due to stretching, is supported by support pins 13 provided in the mold 10 so as to be movable downward, a blow molding step to blow-mold the preform 2 by supplying pressurized liquid L to the preform 2 during the stretching step. When the stretching rod 23 or the support pin 13 does not operate as specified, a preform take-out step is conducted in which the mold 10 is opened to take out the preform 2 without supplying the pressurized liquid in the blow molding step.SELECTED DRAWING: Figure 13

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a liquid-containing container that contains a content liquid from a synthetic resin preform.

Background Art

[0002] Containers made of synthetic resin, such as bottles made of polypropylene (PP) or polyethylene terephthalate (PET), are used for applications that contain various liquids such as beverages, cosmetics, pharmaceuticals, detergents, and toiletries such as shampoo as content liquids. Such containers are generally manufactured by blow molding a synthetic resin preform having the above-described thermoplasticity.

[0003] As blow molding for forming a preform into a container, liquid blow molding is known in which a pressurized liquid is used instead of pressurized air as a pressurizing medium supplied to the inside of the preform.

[0004] For example, Patent Document 1 describes a liquid blow molding method in which a synthetic resin preform is placed in a blow molding mold, and a pressurized liquid is supplied from a pressurized liquid supply source through a nozzle unit into the preform, thereby forming the preform into a container having a predetermined shape along the cavity of the mold.

[0005] According to the liquid blow molding method as described above, by using the content liquid that is finally contained in the container as the liquid supplied to the preform, the molding of the container and the filling of the content liquid into the container are performed simultaneously, and a liquid-containing container containing the content liquid can be manufactured. Therefore, according to the method for manufacturing a liquid-containing container using such liquid blow molding, the filling step of the content liquid into the molded container can be omitted, and the liquid-containing container can be manufactured at low cost.

[0006] In the conventional method for manufacturing a liquid-filled container using liquid blow molding, the container after molding is in a state where it is filled with liquid inside. Therefore, when pressurized liquid is supplied, if the preform is misaligned due to the shaking of the preform or the wall thickness difference, there is a risk that the container will be damaged during liquid blow molding and the content liquid will leak to the outside.

[0007] Therefore, as described in Patent Document 2, for example, during liquid blow molding, while stretching the preform placed in the mold axially with a stretching rod, the bottom of the preform that moves downward due to stretching is supported by a support pin provided in the mold so as to be movable downward, thereby suppressing the occurrence of misalignment of the preform when pressurized liquid is supplied. A method for manufacturing a liquid-filled container has been developed.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0009] However, also in the method for manufacturing a liquid-filled container as described in Patent Document 2, if a predetermined operation such as the stretching rod or the support pin does not stop at a specified initial position or stop position due to malfunction before pressurized liquid is supplied to the preform, the misalignment of the preform cannot be sufficiently suppressed, and the container may be damaged during liquid blow molding and the content liquid may leak to the outside. In the cap attachment process, label attachment process, conveyance process, etc. performed after the blow molding process, the device may be contaminated by the liquid leaking from the container, and there is a risk that production will stop while the contamination is removed by cleaning or the like.

[0010] The present invention has been made in view of such problems, and an object thereof is to provide a method for manufacturing a liquid-containing container capable of preventing a liquid-containing container damaged in liquid blow molding from being formed.

Means for Solving the Problems

[0011] The method for manufacturing a liquid-containing container of the present invention includes a stretching step of axially stretching a synthetic resin preform disposed in a mold with a stretching rod and supporting a bottom portion of the preform that moves downward due to stretching with a support pin provided in the mold so as to be movable downward, and a blow molding step of supplying a liquid pressurized to the preform during the stretching step to blow mold the preform, and is a method for manufacturing a liquid-containing container for manufacturing a liquid-containing container containing a content liquid from the preform, and is characterized in that when the stretching rod or the support pin does not perform a predetermined operation, a preform removal step of opening the mold and removing the preform without supplying the pressurized liquid in the blow molding step is performed.

[0012] The method for manufacturing a liquid-containing container of the present invention, in the above configuration, when the vertical position of the lower end of the stretching rod at the start of the blow molding step deviates from a specified position during the stretching step, it is preferable to perform the preform removal step without supplying the pressurized liquid in the blow molding step.

[0014] The method for manufacturing a liquid-containing container of the present invention, in the above configuration, as the mold, it is preferable to use one having a pair of body molds that open left and right and a bottom mold that moves downward and opens, and the support pin is provided on the bottom mold.

Effects of the Invention

[0015] According to the present invention, it is possible to provide a method for manufacturing a liquid-containing container capable of preventing a liquid-containing container damaged in liquid blow molding from being formed.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0017] Hereinafter, the present invention will be more specifically illustrated and described with reference to the drawings.

[0018] The manufacturing method of the liquid-containing container according to an embodiment of the present invention can be implemented using, for example, a manufacturing apparatus 1 for a liquid-containing container having the configuration shown in FIG. 1.

[0019] The manufacturing apparatus 1 for a liquid-containing container manufactures a liquid-containing container C (see FIG. 11) containing a content liquid from a preform 2 made of a synthetic resin. As the liquid (content liquid) L contained in the liquid-containing container C, various liquids such as beverages, cosmetics, drugs, detergents, and toiletries such as shampoo can be adopted.

[0020] As the preform 2, for example, a bottomed cylindrical shape formed of a synthetic resin material having thermoplasticity such as polypropylene (PP) or polyethylene terephthalate (PET), having a cylindrical mouth portion 2a serving as an open end, a cylindrical body portion 2b connected to the mouth portion 2a, and a hemispherical bottom portion 2c closing the lower end of the body portion 2b can be used.

[0021] Although not shown in detail, on the outer wall surface of the mouth portion 2a, engaging protrusions are provided for attaching a closing cap (not shown) to the mouth portion 2a of the liquid-containing container C after molding by undercut engagement. Note that instead of the engaging protrusions on the outer wall surface of the mouth portion 2a, a male screw may be provided to attach the closing cap to the mouth portion 2a by screw connection.

[0022] As shown in FIGS. 1 and 2, the manufacturing apparatus 1 for a liquid-containing container has a blow molding die 10. The die 10 has a cavity 11 having a shape corresponding to the final shape of the liquid-containing container C such as a bottle shape. The cavity 11 opens upward on the upper surface of the die 10. The preform 2 is mounted on the die 10 in a state where the body portion 2b and the bottom portion 2c are disposed inside the cavity 11 of the die 10 and the mouth portion 2a protrudes upward from the die 10.

[0023] The mold 10 includes a pair of body molds 12a and 12b that open to the left and right, and a bottom mold 12c that moves downward and opens with respect to the body molds 12a and 12b. After the preform 2 is molded into the liquid-containing container C, with the mouth portion 2a held by a conveying device (not shown), the pair of body molds 12a and 12b are opened to the left and right, and the bottom mold 12c is moved downward and opened, so that the liquid-containing container C can be taken out from the mold 10 by the conveying device.

[0024] The bottom mold 12c is provided with a support pin 13. The support pin 13 is supported by the bottom mold 12c so as to be movable in the vertical direction, and can be driven by a drive source such as a servo motor or a hydraulic cylinder (not shown) to move to the rising position protruding upward from the bottom mold 12c, and can be configured to descend from the rising position to the descending position where the upper end is flush with the upper surface of the bottom mold 12c without being driven by the drive source.

[0025] In addition, the mold 10 is provided with a sensor 14 for the support pin. The sensor 14 for the support pin can detect whether or not the support pin 13 has moved to a predetermined rising position. As the sensor 14 for the support pin, for example, a magnetic switch can be used, but other configured sensors may be used as long as they can detect whether or not the support pin 13 has moved to a predetermined rising position.

[0026] Above the mold 10, a nozzle unit 20 for supplying the liquid L pressurized inside the preform 2 is provided.

[0027] The nozzle unit 20 has a main body block 21, and a supply passage 21a for the liquid L is provided inside the main body block 21. Further, at the lower end of the main body block 21, a supply port 21b for the liquid L that is continuous with the supply passage 21a and opens downward is provided. Furthermore, a supply port 21c that is continuous with the supply passage 21a is provided on the side portion of the main body block 21.

[0028] Inside the main body block 21, a seal body 22 is provided. The seal body 22 can open and close the supply port 21b by moving up and down inside the supply path 21a.

[0029] Also, a stretching rod 23 is provided on the main body block 21. The stretching rod 23 penetrates through the seal body 22 and can be driven by the servo motor 15 to move up and down so as to protrude downward from the supply port 21b. The servo motor 15 also functions as a detection means for detecting whether or not the stretching rod 23 has moved to a predetermined position.

[0030] A pressurized liquid supply source 30 is connected to the supply port 21c via a liquid pipe 24. The pressurized liquid supply source 30 is composed of a plunger pump including a cylinder 31 and a piston (plunger) 32, and can supply the liquid L pressurized to a predetermined pressure to the supply path 21a.

[0031] The pressurized liquid supply source 30 is not limited to a plunger pump, and various configurations can be used as long as it can supply the liquid L pressurized to a predetermined pressure to the supply path 21a.

[0032] A tank 40 is connected to the pressurized liquid supply source 30 via a liquid pipe 25. The tank 40 stores the liquid L and supplies the liquid L to the pressurized liquid supply source 30 through the liquid pipe 25. An on-off valve 26 for opening and closing between the pressurized liquid supply source 30 and the tank 40 is provided in the liquid pipe 25.

[0033] Inside the stretching rod 23, a preliminary supply path 23a is provided. The preliminary supply path 23a opens at the lower end of the stretching rod 23 and is connected to the pressurized liquid supply source 30 via the liquid pipe 27 and the liquid pipe 24. An on-off valve 28 for opening and closing between the pressurized liquid supply source 30 and the preliminary supply path 23a is provided in the liquid pipe 27. Inside the stretching rod 23, a preliminary seal body 23b is arranged so as to be movable in the vertical direction. By bringing the preliminary seal body 23b into contact with and separating from the lower end of the stretching rod 23, the lower end opening of the preliminary supply path 23a can be opened and closed.

[0034] A negative pressure supply source 51 is connected to the main body block 21 via an air pipe 50 that is continuous with the supply port 21b on the downstream side of the seal body 22. The negative pressure supply source 51 can supply a negative pressure to the supply port 21b by sucking the air inside the supply port 21b. Three on-off valves 52, 53, and 54 are provided in this order in the air pipe 50 from the side of the supply port 21b toward the negative pressure supply source 51.

[0035] An external communication pipe 55 that branches off from the air pipe 50 is connected to the air pipe 50 between the on-off valves 53 and 54. The end of the external communication pipe 55 is open to the outside. An on-off valve 56 for opening and closing this is provided in the external communication pipe 55.

[0036] Also, an air supply source 58 is connected to the air pipe 50 via an assist air pipe 57 that branches off from the air pipe 50 between the on-off valves 52 and 53. An on-off valve 59 for opening and closing this is provided in the assist air pipe 57. The air supply source 58 can supply air to the supply port 21b via the assist air pipe 57 and the air pipe 50.

[0037] The nozzle unit 20 is movable relative to the mold 10 in the vertical direction. When the nozzle unit 20 descends to the lower stroke end, the lower end of the main body block 21 engages with the mouth portion 2a of the preform 2, and the supply port 21b is liquid-tightly connected to the internal space of the preform 2.

[0038] The manufacturing apparatus 1 for a liquid-containing container has a control unit 60 composed of, for example, a microcomputer or the like. The mold 10, the support pin 13, the sensor 14 for the support pin, the servo motor 15, the nozzle unit 20, the seal body 22, the preliminary seal body 23b, the pressurized liquid supply source 30, the on-off valves 26, 28, 52 to 54, 56, 59, the negative pressure supply source 51, and the air supply source 58 are each connected to the control unit 60, and the operations of these are integrally controlled by the control unit 60. Further, the control unit 60 can determine whether or not the extension rod 23 is performing a predetermined operation based on an input signal from the servo motor 15, and is configured to be able to determine whether or not the support pin 13 is performing a predetermined operation based on an input signal from the sensor 14 for the support pin.

[0039] Next, a method (manufacturing method for a liquid-containing container according to the present embodiment) for manufacturing a liquid-containing container C in which a liquid (content liquid) L is stored inside from a synthetic resin preform 2 using the manufacturing apparatus 1 for a liquid-containing container having the above configuration will be described.

[0040] First, as shown in FIG. 1, the preform 2 heated to a predetermined temperature (for example, 80°C to 150°C) at which extensibility is exhibited is inserted into the mold 10. Next, as shown in FIG. 2, the mold 10 is closed and the preform 2 is placed in the mold 10. At this time, since the mouth portion 2a of the preform 2 is open, the preform 2 is in a state where air fills its interior.

[0041] In the states shown in FIGS. 1 and 2, the seal body 22, the preliminary seal body 23b, the on-off valves 26, 28, 56, 59 are closed, and the on-off valves 52 to 54 are open.

[0042] Next, as shown in FIG. 3, the support pin 13 is moved to the rising position protruding from the bottom mold 12c into the cavity 11, and the upper end of the support pin 13 is opposed to the bottom portion 2c of the preform 2 with a predetermined gap therebetween. At this time, the control unit 60 determines whether or not the support pin 13 has moved to the predetermined rising position based on an input signal from the sensor 14 for the support pin.

[0043] In addition, at the ascending position, the upper end of the support pin 13 may be brought into contact with the bottom 2c of the preform 2 so that the bottom 2c is not deformed.

[0044] Next, in the present embodiment, as shown in FIG. 4, the nozzle unit 20 is lowered, the supply port 21b is connected to the mouth portion 2a of the preform 2, and the stretching rod 23 is moved downward to the prefill position, and the lower end of the stretching rod 23 is opposed to the inner surface of the bottom 2c of the preform 2 with a predetermined gap therebetween. At this time, the control unit 60 determines whether or not the stretching rod 23 has moved to a predetermined prefill position based on an input signal from the servo motor 15.

[0045] Next, a prefill step is performed in which the liquid L is supplied into the preform 2 at a pressure that does not stretch the preform 2 to fill the inside of the preform 2 with the liquid L. More specifically, as shown in FIG. 5, in the prefill step, after the nozzle unit 20 is lowered and the supply port 21b is connected to the mouth portion 2a of the preform 2, the on-off valves 26, 54, 59 and the seal body 22 are closed, and the on-off valves 28, 56 and the preliminary seal body 23b are opened, and the pressurized liquid supply source 30 is operated at a low speed, so that the liquid L is supplied into the preform 2 from the lower end opening of the stretching rod 23 in the prefill position through the preliminary supply path 23a. At this time, the air inside the preform 2 is replaced with the liquid L and exhausted to the outside through the air pipe 50 and the external communication pipe 55 from the supply port 21b. In the prefill step, it is preferable that the preform 2 is not stretched by the pressure of the liquid L and remains in its original shape, but it may be slightly stretched.

[0046] When the prefill step is completed, as shown in FIG. 6, the inside of the preform 2 is filled with the liquid L. When the prefill step is completed, the operation of the pressurized liquid supply source 30 is stopped, and the preliminary seal body 23b and the on-off valves 28, 52, 53, 56 are closed.

[0047] When the prefill process is completed, next, the stretching process is performed. As shown in FIG. 7, in the stretching process, the stretching rod 23 is moved downward from the prefill position and disposed in the mold 10, and the preform 2 disposed in the mold 10 is axially stretched by the stretching rod 23. At the same time, the bottom 2c of the preform 2 that moves downward due to stretching is supported by the support pin 13. At this time, the support pin 13 is pushed by the bottom 2c that moves downward as it is stretched by the stretching rod 23 and moves downward together with the bottom 2c. Therefore, the preform 2 is in a state where the bottom 2c is sandwiched between the stretching rod 23 and the support pin 13, and the body portion 2b is axially (vertically) stretched while core deviation is suppressed.

[0048] Next, the blow molding process is performed during the stretching process. More specifically, as shown in FIG. 8, in the stretching process, when the stretching rod 23 and the support pin 13 descend and the vertical positions of the lower end of the stretching rod 23 and the upper end of the support pin 13 respectively reach predetermined specified positions, the blow molding process is started. In the blow molding process, the on-off valves 26, 28, 52 to 54, 56, 59 and the preliminary seal body 23b are closed, and the seal body 22 is opened. By operating the pressurized liquid supply source 30, the liquid L pressurized to a predetermined pressure (a pressure higher than that in the prefill process) is supplied from the supply port 21b into the preform 2 through the liquid pipe 24 and the supply passage 21a, thereby performing blow molding to axially and radially stretch the body portion 2b and the bottom 2c of the preform 2. At this time, based on the input signal from the servo motor 15, the control unit 60 determines whether or not the stretching rod 23 performs a predetermined operation so that the vertical position of the lower end becomes the specified position when the blow molding process is started. At the same time, based on the input signal from the support pin sensor 14, the control unit 60 determines whether or not the support pin 13 performs a predetermined operation so that the vertical position of the upper end becomes the specified position when the blow molding process is started.

[0049] When the stretching and blow molding steps are completed, the preform 2 is blow-molded into a liquid-filled container C of a predetermined shape that conforms to the cavity 11, as shown in Fig. 9. When the stretching and blow molding steps are completed, the operation of the pressurized liquid supply source 30 is stopped, the seal body 22 is closed, the stretch rod 23 abuts against the bottom mold 12c via the bottom portion 2c, and the support pin 13 is retracted inside the bottom mold 12c.

[0050] As in this embodiment, by performing the stretching step and the blow molding step simultaneously, it is possible to perform biaxial stretch blow molding in which the preform 2 is stretched in the axial direction by the stretch rod 23 while being blow molded by the pressure of the liquid L. Furthermore, by using the stretch rod 23 and the support pin 13 in the stretching step, it is possible to suppress misalignment of the preform 2. This allows the preform 2 to be blow molded into a liquid-filled container C of a predetermined shape that fits the cavity 11 with greater accuracy without damaging the preform 2.

[0051] Furthermore, in this embodiment, a pre-filling process is performed before the blow molding process, thereby preventing air inside the preform 2 from becoming entrained in the liquid L during the blow molding process, causing bubbling, etc., and preventing air from becoming mixed into the liquid L inside the liquid-filled container C formed by the blow molding process.

[0052] The timing for starting the blow molding process may be the same as the timing for starting the stretching process, or may be any time between the start of the stretching process and the completion of the stretching process, or may be after the completion of the stretching process.

[0053] In this embodiment, after the blow molding process and before the mold 10 is opened, a suck-back process is performed to suck out a portion of the liquid (content liquid) L from the liquid-filled container C, thereby preparing the headspace inside the liquid-filled container C.

[0054] In the suck-back process, first, as shown in FIG. 10, starting from the state where the seal body 22 is closed as shown in FIG. 9, the on-off valve 28 and the preliminary seal body 23b are opened. Next, as shown in FIG. 11, from the state shown in FIG. 10, the on-off valves 52 and 59 are opened. In this state, the pressurized liquid supply source 30 is operated in the reverse direction to suck back a part of the liquid L contained inside the liquid-containing container C into the preliminary supply path 23a inside the extension rod 23, while supplying air from the air supply source 58 into the liquid-containing container C through the assist air pipe 57 and the air pipe 50 to prepare the head space inside the liquid-containing container C. The amount of the liquid L sucked back from the liquid-containing container C in the suck-back process is the amount obtained by subtracting the volume of the portion of the extension rod 23 contained in the liquid-containing container C corresponding to the head space from the amount corresponding to the head space. By supplying air from the air supply source 58 into the liquid-containing container C in the suck-back process, a predetermined amount of the liquid L can be sucked back from the liquid-containing container C without deforming the liquid-containing container C into a concave shape, and even when a liquid L with a relatively high viscosity is used as the liquid L, the liquid L can be easily sucked back from the liquid-containing container C through the preliminary supply path 23a.

[0055] Next, as shown in FIG. 12, after raising the extension rod 23 with the preliminary supply path 23a closed toward the nozzle unit 20 to the storage position shown in FIG. 1, the nozzle unit 20 and the extension rod 23 are raised with respect to the mold 10. At this time, by operating the negative pressure supply source 51 with the on-off valves 52 to 54 open, the liquid L adhering near the supply port 21b of the nozzle unit 20 can be sucked through the air pipe 50, and dripping of the liquid from the nozzle unit 20 can be suppressed. When the extension rod 23 rises and detaches from the liquid-containing container C, a predetermined amount of head space H is formed inside the liquid-containing container C, and the liquid-containing container C containing a predetermined amount of the liquid (content liquid) L is completed.

[0056] After the liquid-containing container C is thus completed, as shown in FIG. 1, the pair of body molds 12a and 12b are opened left and right, and the bottom mold 12c is moved downward to open the mold 10. Then, the liquid-containing container C is taken out from the mold 10 using a conveying device (not shown) and conveyed to subsequent processes such as a cap attachment process.

[0057] In the method for manufacturing the liquid-containing container described above, when the stretching rod 23 or the support pin 13 does not perform a predetermined operation, such as not stopping at a specified position due to a malfunction, the stretching rod 23 and the support pin 13 cannot sufficiently suppress the core deviation of the preform 2, and there is a risk that the liquid-containing container C formed by liquid blow molding will be damaged and the content liquid will leak to the outside.

[0058] Therefore, in the method for manufacturing the liquid-containing container of the present embodiment, at a stage before the blow molding step, when the stretching rod 23 or the support pin 13 does not perform a predetermined operation, without supplying the liquid L pressurized in the blow molding step to the preform 2, as shown in FIG. 13, a preform removal step is performed in which the mold 10 is opened and the preform 2 is taken out from the mold 10. For example, when molding is performed simultaneously with a plurality of molds, the preform removal step may be performed for all of the plurality of molds without performing the blow molding step, or among the plurality of molds, only for the mold in which a problem has occurred, without supplying the liquid pressurized in the blow molding step, waiting for the completion of the blow molding step in the other molds, and performing the preform removal step simultaneously with the removal of the liquid-containing container.

[0059] More specifically, in the method for manufacturing the liquid-containing container of the present embodiment, as shown in FIG. 3, based on the input signal from the support pin sensor 14, when the control unit 60 recognizes that the vertical position, i.e., the rising position, of the upper end of the support pin 13 before the start of the stretching step is deviated from the specified position, without performing the blow molding step, after moving the nozzle unit 20 upward, the mold 10 is opened and a preform removal step is performed to take out the preform 2 from the mold 10.

[0060] Also, in the manufacturing method of the liquid-containing container of the present embodiment, as shown in FIG. 4, when the control unit 60 recognizes that the vertical position of the lower end of the stretching rod 23, i.e., the prefill position, deviates from the specified position based on the input signal from the servo motor 15 when starting the prefill process, the mold 10 is opened and the preform 2 is taken out from the mold 10 without performing the blow molding process. A preform removal process is configured to be performed. In this case, it is preferable not to supply the liquid L into the preform 2 in the prefill process either.

[0061] Furthermore, in the manufacturing method of the liquid-containing container of the present embodiment, as shown in FIG. 7, during the stretching process, when the control unit 60 recognizes that the vertical position of the lower end of the stretching rod 23 deviates from the specified position based on the input signal from the servo motor 15 when the blow molding process is started, the mold 10 is opened and the preform 2 is taken out from the mold 10 without performing the blow molding process. A preform removal process is configured to be performed. Note that when the blow molding process is started, it is immediately before the pressurized liquid L is actually supplied into the preform 2 in the blow molding process.

[0062] As described above, in the manufacturing method of the liquid-containing container of the present embodiment, when the stretching rod 23 or the support pin 13 does not perform a predetermined operation at a stage before the blow molding process, the mold 10 is opened and the preform 2 is taken out from the mold 10 without performing the blow molding process. Therefore, it is possible to detect before the blow molding process that there is a risk of core deviation in the preform 2 in the stretching process or the blow molding process, and prevent the formation of the damaged liquid-containing container C that is formed after the blow molding process is performed. Accordingly, it is possible to prevent a problem that the apparatus is contaminated by the liquid L leaking from the damaged liquid-containing container C in the cap attachment process, label attachment process, conveyance process, etc. performed after the blow molding process, and production stops while the contamination is removed by cleaning or the like.

[0063] In particular, if the vertical position, i.e., the rising position, of the upper end of the support pin 13 before the start of the stretching process deviates from the specified position, the preform 2 may be misaligned during the stretching process, making the liquid-filled container C liable to be damaged. However, in the manufacturing method of the liquid-filled container of the present embodiment, when the vertical position (rising position) of the upper end of the support pin 13 before the start of the stretching process deviates from the specified position, the preform removal process is performed. Therefore, it is possible to more reliably prevent the preform 2 from being misaligned in the stretching process or the blow molding process and the liquid-filled container C from being damaged or ruptured by the blow molding process.

[0064] Also, if the prefill position of the stretching rod 23 when starting the prefill process deviates from the specified position, the preform 2 may be misaligned during the stretching process, making the liquid-filled container C liable to be damaged. However, in the manufacturing method of the liquid-filled container of the present embodiment, when the vertical position (prefill position) of the lower end of the stretching rod 23 when starting the prefill process deviates from the specified position, the preform removal process is performed. Therefore, it is possible to more reliably prevent the preform 2 from being misaligned in the stretching process or the blow molding process and the liquid-filled container C from being damaged by the blow molding process.

[0065] Furthermore, if the vertical position of the lower end of the stretching rod 23 when the blow molding process is started during the stretching process deviates from the specified position, the preform 2 may be misaligned during the stretching process, making the liquid-filled container C liable to be damaged. However, in the manufacturing method of the liquid-filled container of the present embodiment, when the vertical position of the lower end of the stretching rod 23 when the blow molding process is started deviates from the specified position, the preform removal process is performed. Therefore, it is possible to more reliably prevent the preform 2 from being misaligned in the stretching process or the blow molding process and the liquid-filled container C from being damaged by the blow molding process.

[0066] In this case, although the interior of the preform 2 is filled with the liquid L in the pre-filling step, since the preform 2 will not be damaged or ruptured by the liquid L supplied in the pre-filling step, by directly taking out the preform 2 filled with the liquid L from the mold 10, the mold 10 can be prevented from being contaminated by the liquid L.

[0067] In the preform removal step, after opening the mold 10 and removing the preform 2 from the mold 10, after checking for and dealing with any defects, as shown in FIG. 1, a new preform 2 is inserted into the mold 10, and by performing each step of the manufacturing method of the liquid-containing container as described above, the liquid-containing container C can be manufactured.

[0068] It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist thereof.

[0069] For example, in the above-described embodiment, it is configured to recognize whether or not the stretching rod 23 has performed a predetermined operation based on an input signal from the servo motor 15 that drives the stretching rod 23. However, the present invention is not limited to this. For example, it may be configured to recognize whether or not the stretching rod 23 has performed a predetermined operation based on an input signal from another sensor such as a position detection sensor provided outside the nozzle unit 20. Similarly, it may be configured to recognize whether or not the support pin 13 has performed a predetermined operation based on an input signal from another sensor such as a position detection sensor provided outside the nozzle unit 20. Further, not limited to the positions of the stretching rod 23 to the support pin 13, when the moving speed or the timing of the start of movement of the stretching rod 23 to the support pin 13 differs from a predetermined speed or timing, it may be configured to determine that the stretching rod 23 to the support pin 13 has not performed a predetermined operation and perform the preform removal step.

[0070] Furthermore, in the above-described embodiment, in addition to the blow molding step, the pre-filling step and the suck-back step are performed. However, these steps do not necessarily have to be performed.

[0071] Furthermore, the method for manufacturing the liquid-containing container can also be carried out using another device different from the manufacturing apparatus 1 for the liquid-containing container.

Explanation of Signs

[0072] 1 Manufacturing apparatus for liquid-containing container 2 Preform 2a Mouth part 2b Body part 2c Bottom part 10 Mold 11 Cavity 12a Body mold 12b Body mold 12c Bottom mold 13 Support pin 14 Sensor for support pin 15 Servo motor 20 Nozzle unit 21 Main body block 21a Supply path 21b Supply port 21c Supply port 22 Sealing body 23 Extension rod 23a Preliminary supply path 23b Preliminary sealing body 24 Liquid pipe 25 Liquid pipe 26 On-off valve 27 Liquid pipe 28 On-off valve 30 Pressurized liquid supply source 31 Cylinder 32 Piston 40 Tank 50 Air pipe 51 Negative pressure supply source 52 On-off valve 53 On-off valve 54 On-off valve 55 External communication pipe 56 On-off valve 57 Assist air pipe 58 Air supply source 59 On-off valve 60 Control unit C Liquid-containing container L Liquid H Headspace

Claims

1. A stretching step of axially stretching a synthetic resin preform disposed in a mold with a stretching rod and supporting a bottom portion of the preform that moves downward due to stretching with a support pin provided movably downward in the mold; A blow molding step of supplying a liquid pressurized to the preform during the stretching step to blow mold the preform, and having, A method for manufacturing a liquid-containing container for manufacturing a liquid-containing container in which a liquid-containing container containing a content liquid is manufactured from the preform, A method for manufacturing a liquid-containing container, characterized in that when the stretching rod or the support pin does not perform a predetermined operation, a preform removal step of opening the mold and removing the preform without supplying the pressurized liquid in the blow molding step is performed.

2. When the vertical position of the lower end of the stretching rod at the start of the blow molding step is deviated from a specified position during the stretching step, the preform removal step is performed without supplying the pressurized liquid in the blow molding step. The method for manufacturing a liquid-containing container according to claim 1.

3. The method for manufacturing a liquid-containing container according to claim 1 or 2, wherein the mold used has a pair of body molds that open to the left and right and a bottom mold that moves downward and opens, and the support pin is provided on the bottom mold.

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