JP6853759B2 - Manufacturing method of liquid container - Google Patents

Description

The present invention relates to a method for manufacturing a liquid-containing container for manufacturing a liquid-containing container containing a content liquid from a synthetic resin preform.

Synthetic resin containers such as polypropylene (PP) bottles and polyethylene terephthalate (PET) bottles contain various liquids such as beverages, cosmetics, chemicals, detergents, and toiletries such as shampoo. It is used for containment purposes. Such a container is generally manufactured by blow molding a preform formed of a synthetic resin material having thermoplasticity as described above.

As blow molding for molding 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.

For example, in Patent Document 1, a preform made of synthetic resin, which has been preheated to a temperature at which stretchability is exhibited, is mounted on a blow molding die, and a blow nozzle is passed through the inside of the preform to add a pump or the like. Described is a liquid blow molding method in which a preform is formed into a container having a predetermined shape along a cavity of a blow molding die by supplying a liquid pressurized to a predetermined pressure by a pressure means. ..

In the liquid blow molding method as described above, by using the content liquid finally stored in the container as a product as the liquid to be supplied to the preform, the container is molded and the container is filled with the content liquid at the same time. This can be carried out to produce a liquid-containing container containing the content liquid. Therefore, according to the method for manufacturing a liquid-containing container using liquid blow molding as described above, the liquid-containing container can be manufactured at low cost by omitting the step of filling the container with the content liquid after molding.

Japanese Patent No. 5806929

In the above-mentioned conventional liquid blow molding method, it is usually required to form a head space of a desired size in the container after molding. As a method of forming the head space, for example, immediately after molding the container containing the liquid, the liquid inside the container is sucked by a pump through a blow nozzle, the inside of the container is made negative pressure, and then the inside of the container is opened to the atmosphere. Therefore, it is conceivable to form a head space by introducing air into the container. However, the liquid existing inside the container immediately after molding is in a foamed state by entraining the air existing inside the preform. Therefore, in the above method, the foamed liquid is introduced into the liquid supply path leading to the blow nozzle, so that air is mixed in the supply path, and the stability of the molding conditions, the moldability of the container, etc. May occur.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a container containing a liquid, which can be manufactured accurately and at low cost so as to have a predetermined content and shape. The purpose is to provide a manufacturing method.

The method for manufacturing a liquid-filled container of the present invention is a method for manufacturing a liquid-filled container for manufacturing a liquid-filled container containing a content liquid from a synthetic resin preform using a nozzle unit and a blow molding mold. The nozzle unit extends from a common path of liquid extending from a pressurized liquid supply source to a branch portion, a liquid supply path extending from the branch portion to a blow nozzle, and a discharge port provided in the discharge rod from the branch portion. It has a liquid discharge path, and supplies the liquid pressurized by the pressurized liquid supply source from the supply path to the inside of the preform in a state where the blow nozzle is engaged with the mouth portion of the preform. Thereby, the liquid blow molding step of molding the preform into the liquid-containing container having a shape along the inner surface of the blow molding mold, and the supply path by operating the pressurized liquid supply source in the suction direction. After discharging the liquid from the inside of the liquid-containing container through the liquid-containing container, the supply path is closed, and the liquid-containing container is connected through the discharge port provided in the discharge rod extending to the inside of the liquid-containing container through the blow nozzle. It has a head space forming step of forming a head space in the liquid-containing container by discharging the liquid from the inside.

In the above configuration, the method for manufacturing a liquid-containing container of the present invention is to operate the pressurized liquid supply source in the suction direction in the head space forming step to operate the liquid-containing container through the discharge port of the discharge rod. It is preferable to discharge the liquid from the inside.

In the method for producing a liquid-containing container of the present invention, in the above configuration, in the headspace forming step, a pressurized gas is introduced into the liquid-containing container to enter the liquid through the discharge port of the discharge rod. It is preferable to drain the liquid from the inside of the container.

In the above configuration, the method for manufacturing a liquid container of the present invention discharges a liquid from the discharge port of the discharge rod in the liquid inside the preform before and / or during molding into the liquid container. It is preferable to further have a rod purging step.

In the method for manufacturing a container containing liquid of the present invention, in the rod purging step, the entire amount of liquid discharged from the inside of the container containing liquid through the discharge port in the head space forming step performed last time is used as the discharge port. It is preferable to discharge from.

In the method for manufacturing a container containing a liquid of the present invention, in the above configuration, air discharge to discharge the air inside the preform to the outside by supplying the liquid to the inside of the preform before the liquid blow molding step. It is preferable to have additional steps.

In the method for manufacturing a liquid container of the present invention, in the above configuration, the amount of liquid discharged from the inside of the liquid container through the discharge port in the head space forming step is equal to or less than the internal volume of the discharge path. preferable.

In the above configuration, the method for producing a container containing a liquid of the present invention further includes a rod stretching step of stretching the preform in the axial direction by a stretching rod during the liquid blow molding step or before the liquid blow molding step. However, the discharge rod is preferably the extension rod.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a method for producing a liquid-containing container, which can be produced accurately and at low cost so that the liquid-containing container has a predetermined content and shape.

It is explanatory drawing which shows an example of the manufacturing apparatus of the liquid containing container used in the manufacturing method of the liquid containing container which is one Embodiment of this invention in the state of performing a standby process. It is explanatory drawing which shows the manufacturing apparatus of the container containing a liquid in the state which performs the air discharge process. It is explanatory drawing which shows the manufacturing apparatus of the container containing a liquid in the state which performs the rod purging process and the liquid blow molding process. It is explanatory drawing which shows the manufacturing apparatus of the container containing liquid at the time of completion of a liquid blow molding process. It is explanatory drawing which shows the manufacturing apparatus of the liquid-filled container in the state which the 1st stage suckback is performed in the head space formation process. It is explanatory drawing which shows the manufacturing apparatus of the liquid container when the supply path is closed from the state of FIG. 5 in the head space formation process. It is explanatory drawing which shows the manufacturing apparatus of the liquid-filled container in the state which started the second-stage sackback from the state of FIG. 6 in the head space formation step, and has formed the head space. It is explanatory drawing which shows the manufacturing apparatus of the container containing a liquid in the state which the rod raising / depressurizing process is performed.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The method for manufacturing a liquid-containing container according to an embodiment of the present invention is a method for manufacturing a liquid-containing container containing a liquid-containing liquid from a synthetic resin preform using a nozzle unit and a blow molding mold. In the manufacturing method, the nozzle unit has a common liquid path extending from the pressurized liquid supply source to the branch portion, a liquid supply path extending from the branch portion to the blow nozzle, and a discharge port provided in the discharge rod from the branch portion. By supplying the liquid pressurized by the pressurized liquid supply source from the supply path to the inside of the preform with the blow nozzle engaged with the mouth of the preform, which has a liquid discharge path extending to the inside of the preform. A liquid blow molding step of molding a preform into a liquid-filled container shaped along the inner surface of a blow-molding mold, and a liquid-filled container through the supply path by operating the pressurized liquid supply source in the suction direction. After discharging the liquid from the inside, the supply path is closed, and the liquid is discharged from the inside of the liquid-containing container through the discharge port provided on the discharge rod extending to the inside of the liquid-containing container through the blow nozzle. It is a method for manufacturing a liquid-containing container, which comprises a head space forming step of forming a head space.

In the method for manufacturing a liquid container of the present embodiment, in the headspace forming step, the pressurized liquid supply source is operated in the suction direction so that the liquid is discharged from the inside of the liquid container through the discharge port of the discharge rod. ing.

In the method for manufacturing a liquid container of the present embodiment, in the headspace forming step, a pressurized gas is introduced into the liquid container, so that the liquid is discharged from the inside of the liquid container through the discharge port of the discharge rod. I am trying to do it.

The method for manufacturing a liquid container of the present embodiment further includes a rod purging step of discharging the liquid from the discharge port of the discharge rod in the liquid inside the preform before and / or during molding into the liquid container. are doing.

In the method for manufacturing the liquid container of the present embodiment, in the rod purging step, the entire amount of the liquid discharged from the inside of the liquid container is discharged from the discharge port through the discharge port in the head space forming step performed last time.

In the method for manufacturing a container containing a liquid of the present embodiment, in the rod purging step, the liquid is discharged from the discharge port of the discharge rod in the liquid.

The method for manufacturing a container containing a liquid of the present embodiment further includes an air discharge step of supplying the liquid inside the preform before the liquid blow molding step to discharge the air inside the preform to the outside. There is.

In the method for manufacturing a liquid container of the present embodiment, the amount of liquid discharged from the inside of the liquid container through the discharge port in the head space forming step is equal to or less than the internal volume of the discharge path.

The method for manufacturing a container containing liquid of the present embodiment further includes a rod stretching step of stretching the preform in the axial direction by a stretching rod during the liquid blow molding step, and the discharge rod is a stretching rod.

Such a method for manufacturing a liquid-containing container of the present embodiment can be carried out using, for example, the liquid-containing container manufacturing apparatus 1 having the configuration shown in FIG.

The liquid-containing container manufacturing apparatus 1 shown in FIG. 1 manufactures a liquid-containing container C (see FIG. 4) containing the content liquid from the synthetic resin preform 2. As the liquid (content liquid) L contained in the liquid-containing container C, various liquids L such as toiletries such as beverages, cosmetics, chemicals, detergents, and shampoos can be adopted.

As the preform 2, for example, a synthetic resin material having thermoplasticity such as polypropylene (PP) or polyethylene terephthalate (PET) connects the cylindrical mouth portion 2a as the opening end and the mouth portion 2a and closes the lower end. A bottomed tubular shape having a cylindrical body portion 2b can be used.

Although details are not shown, on the outer wall surface of the mouth portion 2a, an engagement protrusion for attaching a closing cap (not shown) to the mouth portion 2a of the liquid container C after molding by tapping (undercut engagement). Is provided. In addition, a male screw may be provided on the outer wall surface of the mouth portion 2a instead of the engaging protrusion, and the closing cap may be attached to the mouth portion 2a by screw connection.

The liquid container manufacturing apparatus 1 has a blow molding die 10. The blow molding die 10 has a cavity 11 having a shape corresponding to the final shape of the liquid container C such as a bottle shape. The cavity 11 opens upward on the upper surface of the blow molding die 10. In the preform 2, the body 2b is arranged inside the cavity 11 of the blow molding die 10, and the mouth 2a protrudes upward from the blow molding die 10. It is attached to.

The blow molding die 10 can be opened to the left and right. By forming the preform 2 into the liquid container C and then opening the blow molding die 10 to the left and right, the liquid container can be opened. C can be taken out from the blow molding die 10.

Above the blow molding die 10, a nozzle unit 20 for supplying the pressurized liquid L is provided inside the preform 2. The nozzle unit 20 has a main body block 21.

A support block 22 is provided at the lower end of the main body block 21, and a blow nozzle 23 is attached to the lower end of the main body block 21 supported by the support block 22. The blow nozzle 23 is formed in a substantially cylindrical shape, and the inside of the lower end portion thereof is a liquid supply port 23a. The nozzle unit main body 20a is composed of the main body block 21, the support block 22, and the blow nozzle 23. The nozzle unit main body 20a is movable relative to the blow molding die 10 in the vertical direction. When the nozzle unit body 20a descends to the lower stroke end, the nozzle unit body 20a (more specifically, the blow nozzle 23) is attached to the mouth portion 2a of the preform 2 mounted on the blow molding die 10. Engage in a sealed state from above.

Inside the nozzle unit main body 20a (more specifically, the main body block 21 and the blow nozzle 23), a vertical flow path 24 extending to the liquid supply port 23a of the blow nozzle 23 is provided. The vertical flow path 24 extends in the vertical direction.

The nozzle unit main body 20a (more specifically, the main body block 21) is provided with a supply port 25 communicating with the upper end of the vertical flow path 24.

The nozzle unit main body 20a (more specifically, the blow nozzle 23) has an annular (annular) seat portion 24a provided in the vertical flow path 24. The annular seat 24a is composed of the upper surface of the blow nozzle 23. The annular seat portion 24a may be formed by the inner peripheral surface of the blow nozzle 23, or may be formed by the upper surface and the inner peripheral surface of the blow nozzle 23. The annular seat 24a is formed of a downward conical tapered surface. However, the shape of the annular seat 24a can be changed as appropriate. Inside the vertical flow path 24, a seal body 26 for opening and closing (the seat portion 24a) of the vertical flow path 24 is arranged. The seal body 26 is formed in a cylindrical shape, and a downward conical tapered surface 26a is provided at the lower end of the seal body 26. When the seal body 26 moves to the closed position, which is the stroke end position on the lower side, the seal body 26 comes into contact with the upper surface (seat portion 24a) of the blow nozzle 23 on the tapered surface 26a and comes into contact with the vertical flow path 24 (seat portion 24a). To block. The tapered surface 26a is provided at the lower end of the seal body 26, but its arrangement can be changed as appropriate. Further, the tapered surface 26a has a downward conical shape, but the shape thereof can be changed as appropriate. On the other hand, when the seal body 26 moves upward from the closed position, the lower end surface of the seal body 26 is separated from the upper surface (seat portion 24a) of the blow nozzle 23, and the vertical flow path 24 (seat portion 24a) is opened. To.

The seal body 26 has a closed position for closing the vertical flow path 24 (seat portion 24a) and a maximum opening degree of the vertical flow path 24 (seat portion 24a), which is the maximum opening degree in the liquid blow molding process. It is possible to move between the open position and the open position. More specifically, the seal body 26 is movable between the closed position (see FIG. 1), the preliminary opening position (see FIG. 2), and the opening position (see FIG. 4). At the preliminary opening position, the opening degree of the seal body 26 that opens and closes the vertical flow path 24 (the seat portion 24a) is smaller than the opening degree at the opening position. Preferably, the effective cross-sectional area of the vertical flow path 24 at the preliminary open position is 10% or less of the effective cross-sectional area of the vertical flow path 24 at the open position. As shown in FIG. 1, the seal body 26 is fixed to a shaft body 27 provided so as to be movable in the vertical direction relative to the nozzle unit main body 20a, and is movable in the vertical direction inside the vertical flow path 24. It has become. The seal body 26 may be formed integrally with the shaft body 27.

The nozzle unit 20 has a discharge rod 28 provided with a discharge port 28a. The discharge rod 28 formed in a substantially columnar shape made of a steel material or the like extends along the axis of the shaft body 27 and the seal body 26. The discharge rod 28 can be driven by a drive source (not shown) and can move in the vertical direction relative to the shaft body 27 and the seal body 26. The discharge port 28a communicates with the first pipe P1 via a hollow portion (not shown) of the discharge rod 28. More specifically, the lower end of the hollow portion of the discharge rod 28 communicates with the discharge port 28a, and the upper end of the hollow portion of the discharge rod 28 communicates with the first pipe P1. A rod valve V1 is provided in the first pipe P1, and the rod valve V1 can open and close the first pipe P1. The rod valve V1 is preferably composed of a solenoid valve that can be controlled by a control device. In the present embodiment, the lower end of the discharge rod 28 is closed, and the discharge port 28a is provided on the peripheral wall of the discharge rod 28. Therefore, when the discharge rod 28 is pulled back to the original position after the head space HS (see FIG. 7) of the container C is formed, dripping is unlikely to occur. However, the present invention is not limited to such a configuration, and the discharge port 28a may be provided on the lower end surface of the discharge rod 28 or on both the lower end surface and the peripheral wall.

The discharge rod 28 may be used as a stretching rod as in the present embodiment. The discharge rod 28 can extend the preform 2 in the axial direction by moving downward.

Inside the nozzle unit 20 (nozzle unit main body 20a), a flow path 29 through which a liquid L and / or a gas (air in this embodiment) flows is provided. The flow path 29 is a portion of the supply path described later (the supply path is composed of the third pipe P3, the supply port 25, and the vertical flow path 24) on the downstream side of the seat portion 24a (in the present embodiment, the blow nozzle 23. A suction state in which the opening 31 provided on the inner peripheral surface) is connected to a suction source 32 capable of sucking the liquid L in the flow path 29, and a pressurized gas (air in the present embodiment) is supplied to the opening 31. A pressurized state connected to a possible pressurized gas supply source 33, an open state in which the opening 31 is connected to the atmosphere, and the opening 31 blocked from the suction source 32, the pressurized gas supply source 33, and the air. It is configured so that it can be selectively selected from the closed state. As shown in FIGS. 1 and 8, by putting the flow path 29 in the suction state, it is possible to prevent dripping from the blow nozzle 23. When the content is a liquid that does not easily cause dripping or when dripping may occur, it is not necessary to put the flow path 29 in a suction state (a configuration in which the third path 29c and the suction source 32 are not provided). May be). As shown in FIG. 2, by opening the flow path 29 to the atmosphere, air can be discharged from the inside of the preform 2 to the atmosphere (outside) through the flow path 29 in the air discharge step. Depending on the conditions, in the air discharge step, the path 29 may be in a suction state instead of being open to the atmosphere, and air may be discharged from the inside of the preform 2. As shown in FIGS. 3 and 4, by closing the flow path 29, the pressurized liquid L can be stably supplied to the inside of the preform 2 in the liquid blow molding step. As shown in FIG. 7, by putting the flow path 29 in a pressurized state, when the liquid L is discharged from the inside of the preform 2 through the discharge port 28a of the discharge rod 28 in the head space forming step, the preform 2 is discharged. By supplying a pressurized gas (air) to the inside, the discharge of the liquid L can be promoted or supported. The suction source 32 can be configured by, for example, a suction pump or the like. The pressurized gas supply source 33 can be configured by, for example, a pressurized pump or the like. The suction source 32 and the pressurized gas supply source 33 may be composed of a suction / pressurizing pump (for example, a plunger pump such as the pressurized liquid supply source 30) in which the suction pump and the pressurizing pump are integrated. .. A part or the whole of the flow path 29 can be provided inside the nozzle unit 20 (nozzle unit main body 20a).

In the present embodiment, as shown in FIG. 1, the flow path 29 includes a first path 29a provided with the first valve Va, a second path 29b provided with the second valve Vb, and a third valve Vc. It has a provided third path 29c, a fourth path 29d provided with a fourth valve Vd, and a fifth path 29e provided with a fifth valve Ve. One end of the first path 29a is connected to the opening 31, and the other end is connected to the first branch 34. One end of the second path 29b is connected to the second branch 35, and the other end is open to the atmosphere. One end of the third path 29c is connected to the second branch 35, and the other end is connected to the suction source 32. One end of the fourth path 29d is connected to the first branch 34, and the other end is connected to the second branch 35. One end of the fifth path 29e is connected to the first branch portion 34, and the other end is connected to the pressurized gas supply source 33. The first to fifth valves Va to Ve are preferably composed of solenoid valves.

The pressurized liquid supply source 30 is connected to the supply port 25 by the second pipe P2. The pressurized liquid supply source 30 can be composed of, for example, a plunger pump including a cylinder 30a and a piston (plunger) 30b.

As shown in FIGS. 3 and 4, the pressurized liquid supply source 30 has the blow nozzle 23 engaged with the mouth portion 2a of the preform 2 mounted on the blow molding die 10 in a sealed state, and the seal body 26. Operates in the forward direction (pressurizing direction) in a state where the vertical flow path 24 is open, so that the second pipe P2, the third pipe P3, the supply port 25, and the vertical flow path 24 (the seat portion 24a and the liquid supply) are supplied. The pressurized liquid L can be supplied to the inside of the preform 2 through the mouth 23a). The second pipe P2 is branched into the first pipe P1 and the third pipe P3 at the branch portion S. The nozzle unit 20 has a common path composed of a second pipe P2 extending from the pressurized liquid supply source 30 to the branch portion S, and a third pipe P3, a supply port 25, and a vertical flow path extending from the branch portion S to the supply port 25. It has a supply path composed of 24 and a discharge path (including the first pipe P1) extending from the branch portion S to the discharge port 28a provided on the discharge rod 28.

As shown in FIG. 7, the pressurized liquid supply source 30 operates in the opposite direction when the sealing body 26 closes the vertical flow path 24 and the rod valve V1 is open, so that the discharge port 28a of the discharge rod 28 Through the liquid L, the liquid L can be discharged from the inside of the liquid container C into the discharge path from the discharge port 28a to the branch portion S.

The pressurized liquid supply source 30 operates in the opposite direction in a state where the seal body 26 closes the vertical flow path 24 and the rod valve V1 is closed, so that the liquid L stored in the supply tank (not shown) is stored in the cylinder 30a. Can be sucked into the inside to prepare for the next liquid blow molding.

Nozzle unit body 20a, seal body 26, discharge rod (stretching rod) 28, pressurized liquid supply source 30 (plunger 30b), rod valve V1, first to fifth valves Va to Ve, suction source 32 and pressurized gas The operation of the supply source 33 and the like is integrally controlled by a control device (not shown).

Next, using the liquid-containing container manufacturing apparatus 1 having such a configuration, the liquid-containing container C in which the liquid (content liquid) L is contained inside the container having a predetermined shape from the synthetic resin preform 2 is formed. A molding method (a method for manufacturing a container containing a liquid according to the present embodiment) will be described.

First, a standby process is performed. In the standby step, the preform 2 which has been preheated to a predetermined temperature (for example, 80 ° C. to 150 ° C.) to the extent that stretchability is exhibited by using a heating means (not shown) such as a heater is used for blow molding. It is attached to the mold 10 and fastened.

At this time, as shown in FIG. 1, the nozzle unit 20 is located at a position upwardly separated from the blow molding die 10, and the seal body 26 is in a state of closing the seat portion 24a. Further, the flow path 29 is in a suction state. More specifically, the first valve Va is open, the second valve Vb is closed, the third valve Vc is open, the fourth valve Vd is open, and the fifth valve Ve is closed. At this time, since the mouth portion 2a of the preform 2 is open, the preform 2 is in a state of being filled with air.

Next, in this embodiment, an air discharge step is performed. In the air discharge step, as shown in FIG. 2, the sealed body is in a state where the nozzle unit 20 is lowered, the blow nozzle 23 is engaged with the mouth portion 2a of the preform 2, and the flow path 29 is open to the atmosphere. The 26 is moved to the preliminary open position, the plunger 30b is operated in the forward direction at the first speed (that is, at the first pressure), and the liquid L is supplied from the vertical flow path 24 (supply path) to the inside of the preform 2. By doing so, the air inside the preform 2 is discharged to the atmosphere (outside) through the flow path 29. That is, by supplying the liquid L to the inside of the preform 2, most of the air filled inside the preform 2 is pushed out by the liquid L to be discharged. At this time, in the flow path 29, the first valve Va is open, the second valve Vb is open, the third valve Vc is closed, the fourth valve Vd is open, and the fifth valve Ve is closed. The first speed in the air discharge step is preferably set so as not to substantially stretch (expand) the preform.

When the air discharge step is completed, the liquid blow molding step is then performed. In the liquid blow molding step, the blow nozzle 23 is engaged with the mouth portion 2a of the preform 2, and the pressure is applied from the vertical flow path 24 (supply path) to the inside of the preform 2 by the pressurized liquid supply source 30. By supplying the liquid L, the preform 2 is formed into a liquid-containing container C having a shape along the cavity 11 of the blow molding die 10.

In the present embodiment, as shown in FIG. 3, a rod purging step is first performed at the beginning of this liquid blow molding step. In the rod purging step, first, the flow path 29 is closed, the rod valve V1 is opened, and then the plunger 30b is moved at a second speed higher than the first speed while holding the seal body 26 in the preliminary open position ( That is, it is operated in the forward direction (at a second pressure higher than the first pressure), and in the liquid L inside the preform 2 before and / or during molding into the liquid-containing container C, the discharge port 28a of the discharge rod 28 Liquid L is discharged from. In the present embodiment, both the first to fifth valves Va to Ve are closed in the rod purging step and the liquid blow molding step. However, the third valve Vc may be opened in advance in preparation for the rod raising / depressurizing step. Further, the fifth valve Ve may be opened in advance in preparation for the second stage sackback in the head space forming step.

In the previous headspace forming step, the liquid L discharged from the discharge port 28a of the discharge rod 28 may be mixed with some air due to the process of vertical movement of the discharge rod 28, etc., and this air may be mixed in the vertical flow path 24 (the vertical flow path 24 ( If it is returned to the supply path) and accumulated every time the container C is molded, the stability of the molding conditions (pressurization pressure of the liquid L during liquid blow molding, etc.) and the moldability of the container are deteriorated. There is a risk. If the liquid L (preferably the entire amount) discharged from the discharge port 28a of the discharge rod 28 in the previous head space forming step is discharged to the inside of the preform 2 by the rod purge step, air is accumulated in this way. Can be prevented. Further, in the rod purging step described above, since the amount of air supplied to the inside of the preform 2 is small, the influence on the moldability can be ignored. In the rod purging step, the liquid L is discharged from the discharge port 28a in the liquid L inside the preform 2. Therefore, it is possible to suppress the occurrence of foaming inside the preform 2.

In the present embodiment, the rod purging step is performed by operating the plunger 30b in the forward direction at the second speed while holding the seal body 26 in the preliminary open position, but the seal body 26 is moved to the open position. While or after moving to the open position, the plunger 30b may be operated in the forward direction at the second speed. Further, in order to realize more stable discharge from the discharge port 28a in the rod purging step, after moving the seal body 26 to the closed position, the rod valve V1 is opened and the plunger 30b is operated in the forward direction (for example). , Second speed). Alternatively, an on-off valve may be provided in the third pipe P3 to close the on-off valve and open the rod valve V1 (at this time, the seal body 26 may be held in the preliminary open position or moved to the open position. Good), the plunger 30b may be actuated in the forward direction (eg, second speed).

In the liquid blow molding step, when the rod purging step is completed, the seal body 26 is then raised from the preliminary open position to the open position while the plunger 30b is operating in the forward direction at the second speed, and the vertical flow is performed. The liquid L pressurized to the second pressure is supplied to the inside of the preform 2 from the passage 24 (supply passage) through the seat portion 24a. As a result, as shown in FIG. 4, the preform 2 is formed into a liquid-containing container C having a shape along the cavity 11 of the blow molding die 10.

Here, since the liquid blow molding step is performed in a state where most of the air inside the preform 2 is discharged to the outside in the air discharge step, when the pressurized liquid L is supplied to the inside of the preform 2. The liquid L does not entrain air in the liquid L, which suppresses the mixing of air into the liquid L inside the liquid container C.

In this embodiment, as shown in FIGS. 3 and 4, the rod stretching step is performed during the liquid blow molding step. In the rod stretching step, the body portion 2b of the preform 2 is stretched in the axial direction (longitudinal direction) by the stretching rod 28 that advances and moves downward. The rod stretching step may be performed before the liquid blow molding step. By performing the liquid blow molding step after or during the rod stretching step (the rod stretching step may be started after the start of the liquid blow molding step), the preform 2 is stretched axially by the stretching rod 28. Since biaxial stretch blow molding for blow molding can be performed, the preform 2 can be more accurately molded into a liquid-containing container C having a predetermined shape. However, the liquid blow molding step may be performed without performing the rod stretching step. FIG. 1 shows a state in which the extension rod 28 is in the in-situ position. The lower end surface of the extension rod 28 does not have to be located at the height shown in FIG. 1 in the original position, and may be located above or below the height.

When the liquid blow molding step is completed, the headspace forming step is then performed. As shown in FIG. 5, in the present embodiment, in the head space forming step, first, the first stage of suckback is performed (that is, the pressurized liquid supply source 30 is operated in the suction direction to allow the liquid to pass through the supply path. Liquid L is discharged from the inside of the container C). In the first-stage sackback, as shown in FIG. 5, the seal body 26 is in the open position, the flow path 29 is in the closed state, and the rod valve V1 remains open (the rod valve V1 may be closed). , The plunger 30b is operated in the opposite direction (suction direction) by a predetermined amount of operation, and a predetermined amount of liquid L is sucked back into the vertical flow path 24 (supply path) from the inside of the molded liquid container C. By this first-stage suckback, the positive pressure state inside the container C is eliminated (may be a negative pressure state), and then when the flow path 29 is put into a pressurized state, the liquid L is released from the inside of the container C. Can be suppressed from entering the flow path 29. Further, by performing this first-stage bagback through the vertical flow path 24 (supply path), the liquid L can be discharged more quickly than when it is performed only through the discharge port 28a of the discharge rod 28, and the inside of the container C can be discharged. The positive pressure state can be quickly eliminated. The amount of suction back by the first-stage sackback is limited to a small amount so that a small amount of air mixed in the liquid L inside the container C after molding is not returned to the vertical flow path 24 (supply path) as much as possible. Is preferable.

In the present embodiment, in the head space forming step, when the first-stage suckback is completed, the seal body 26 is moved to the closed position (see FIG. 6), the flow path 29 is in a pressurized state, and the second-stage. Suck back (see FIG. 7). More specifically, as shown in FIG. 7, the flow path 29 has the first valve Va opened, the second valve Vb closed, the third valve Vc closed, the fourth valve Vd closed, and the fifth valve Ve. Is open. However, the third valve Vc may be opened in advance in preparation for the rod raising / depressurizing step. In the second-stage sackback, the rod valve V1 is opened and the pressurized liquid supply source 30 (plunger 30b) is operated in the suction direction while the vertical flow path 24 (supply path) is closed. The liquid L is discharged from the inside of the liquid container C through the discharge port 28a provided on the discharge rod 28 extending to the inside of the liquid container C through the blow nozzle 23, and a headspace HS is formed in the liquid container C. In the present embodiment, since the second-stage suckback is performed while supplying the pressurized gas from the flow path 29 to the inside of the preform 2, the discharge of the liquid L through the discharge port 28a is promoted. .. This support by the pressurized gas is particularly effective when the viscosity of the liquid L as the content liquid is high. When the liquid L can be discharged from the discharge port 28a without the support of the pressurized gas, such as when the viscosity of the liquid L as the content liquid is small, the flow path 29 is opened to the atmosphere (or , The blow nozzle 23 may be separated from the mouth portion 2a of the container C so that the atmosphere can be introduced from the outside, and the second-stage suckback may be performed. In this way, when performing the second-stage sackback while introducing gas into the preform 2, the flow path 29 is closed and the inside of the container C is negatively pressured by the second-stage sackback. After that, as compared with the case where the flow path 29 is opened to the atmosphere to form the head space HS, it is possible to form a larger head space HS without causing deformation (permanent deformation) due to excessive negative pressure in the container C. it can. However, the flow path 29 may be closed, the inside of the container C may be negatively pressured by the second-stage suckback, and then the flow path 29 may be opened to the atmosphere to form the headspace HS. In this case, the second-stage sackback may be performed at the same time as the first-stage sackback (including partial overlap due to a time difference). Further, instead of the second-stage sackback, the liquid L is discharged through the discharge port 28a only by the pressurized gas from the flow path 29 (that is, the pressurized liquid supply source 30 is discharged with the supply path blocked. By introducing the pressurized gas into the liquid-filled container C without operating in the suction direction, the liquid L is discharged from the inside of the liquid-filled container C through the discharge port 28a of the discharge rod 28), and the headspace HS is created. It may be formed.

According to the discharge of the liquid L through the discharge port 28a as in the present embodiment, the liquid L is discharged through the vertical flow path 24 (the seat portion 24a), which is lower than the case where the air is less mixed. The liquid L can be discharged from the portion of. Therefore, when performing the rod purging step, it is not essential to return the entire amount of the liquid L discharged through the discharge port 28a in the rod purging step (the amount expected to be mixed with air may be returned). In particular, in the present embodiment, as shown in FIG. 7, the discharge port 28a located in the lower half LP (lower part when the height is bisected up and down) of the liquid container C with less air mixing is located. The liquid L is discharged from the inside of the liquid container C through the container C. Instead of this, the liquid L may be discharged from the inside of the liquid container C through the discharge port 28a located in the upper half of the liquid container C. A plurality of discharge ports 28a may be provided on the discharge rod 28 along the axial direction and / or the circumferential direction. The arrangement position, number, shape, etc. of the discharge port 28a can be appropriately set according to the type, properties, etc. of the liquid L.

Further, in the head space forming step, the amount of the liquid L discharged from the inside of the liquid container C through the discharge port 28a is set to be equal to or less than the internal volume of the discharge path. Therefore, it is possible to prevent the discharged liquid L from being mixed with the air into the supply path (longitudinal flow path 24, supply port 25, and third pipe P3). From this viewpoint, it is preferable that the amount of the liquid L discharged from the inside of the liquid container C through the discharge port 28a in the head space forming step is equal to or less than the internal volume from the discharge port 28a to the rod valve V1 in the discharge path. Further, according to the present embodiment, the pressurized liquid supply source 30 for pressurizing the supply path can also be used for this discharge, and the configuration of the nozzle unit 20 can be simplified. However, in the headspace forming step, the amount of the liquid L discharged from the inside of the liquid container C through the discharge port 28a may be larger than the internal volume of the discharge path.

In the present embodiment, when the head space forming step is completed, the rod raising / depressurizing step is performed. In the rod raising / depressurizing step, as shown in FIG. 8, the discharge rod (stretching rod) 28 is raised and returned to the original position. Further, the flow path 29 is brought into the suction state, and the rod valve V1 is closed. Next, the nozzle unit 20 is raised, and the liquid-containing container C is taken out from the blow molding mold 10. Then, the pressurized liquid supply source 30 is filled, and the process proceeds to the standby process shown in FIG.

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

For example, in the above embodiment, the case where the method for manufacturing the liquid container of the present invention is performed using the liquid container manufacturing apparatus 1 having the configuration shown in FIG. 1, is shown, but the manufacturing of the liquid container having another configuration is shown. The method for producing a container containing a liquid of the present invention can also be carried out using an apparatus or the like.

In the above embodiment, the inside of the preform 2 is opened to the atmosphere by opening the flow path 29 to the atmosphere with the blow nozzle 23 engaged with the mouth portion 2a of the preform 2 in the air discharge step. However, it is not limited to this. For example, in the air discharge step, the blow nozzle 23 may not be engaged with the mouth portion 2a of the preform 2 to secure an air discharge passage from the inside to the outside of the preform 2.

In the above embodiment, the pressurized liquid supply source 30 is a plunger pump, but the present invention is not limited to this, and the liquid L can be pressurized to a predetermined pressure and supplied to the preform 2, and the liquid can be supplied. Various configurations such as other types of pumps can be used as long as they can generate a negative pressure for the suckback of L.

In the above embodiment, in the rod purging step, the liquid L is discharged from the discharge port 28a of the discharge rod 28 in the liquid L inside the preform 2 before and / or during molding into the liquid container C. I tried to do it, but it is not limited to this. For example, in the rod purging step, the liquid L may be always discharged from the discharge port 28a of the discharge rod 28 in the air. Further, in the above-described embodiment, in the rod purging step, the liquid L is always discharged from the discharge port 28a in the liquid L inside the preform 2, but for example, air is initially discharged. It may be carried out in the liquid L and then in the liquid L. Further, a step of supplying the liquid L to the inside of the preform 2 in advance by means other than the blow nozzle 23 may be provided before the rod purging step (for example, before the standby step). Further, in the above-described embodiment, the rod purging step is performed during the liquid blow molding step, but is not limited to this. For example, the rod purge step may be performed before or during the liquid blow molding step (for example, before or during the air discharge step, or between the air discharge step and the liquid blow molding step). Further, in the rod purging step, the liquid L is discharged from the discharge port 28a of the discharge rod 28 in the liquid L inside the liquid container C immediately after molding (before the first-stage suckback) depending on the conditions. You may go. The rod purging step may not be performed.

In the above-described embodiment, the air discharge step is performed, but the air discharge step may not be performed.

As the preform 2, various shapes can be used depending on the shape of the liquid container C after molding and the like.

1 Liquid container manufacturing equipment 2 Preform 2a Mouth 2b Body 10 Blow molding mold 11 Cavity 20 Nozzle unit 20a Nozzle unit Main body 21 Main body block 22 Support block 23 Blow nozzle 23a Liquid supply port 24 Vertical flow path 24a Seat Part 25 Supply port 26 Seal body 26a Tapered surface 27 Shaft body 28 Discharge rod (stretching rod)
28a Discharge port 29 Flow path 30 Pressurized liquid supply source 30a Cylinder 30b Piston (plunger)
31 Opening 32 Suction source 33 Pressurized gas supply source 34 First branch 35 Second branch C Liquid container L Liquid P1 First pipe P2 Second pipe P3 Third pipe S Branch V1 Rod valve Va to Ve 1st ~ 5th valve HS headspace LP lower half

Claims (9)

A method for manufacturing a liquid-containing container in which a liquid-containing container containing a content liquid is manufactured from a synthetic resin preform using a nozzle unit and a blow molding die.
The nozzle unit includes a common path for liquid extending from a pressurized liquid supply source to a branch portion, a liquid supply path extending from the branch portion to a blow nozzle, and a liquid extending from the branch portion to a discharge port provided on a discharge rod. Has a discharge route and
The preform is blown by supplying the liquid pressurized by the pressurized liquid supply source from the supply path into the inside of the preform with the blow nozzle engaged with the mouth portion of the preform. A liquid blow molding step of molding into the liquid container having a shape along the inner surface of the molding die, and
By operating the pressurized liquid supply source in the suction direction, the liquid was discharged from the inside of the liquid container through the supply path, and then the supply path was closed and extended to the inside of the liquid container through the blow nozzle. A method for manufacturing a liquid-containing container, which comprises a head space forming step of forming a head space in the liquid-containing container by discharging a liquid from the inside of the liquid-containing container through the discharge port provided on the discharge rod. .. The liquid-filled container according to claim 1, wherein in the headspace forming step, the liquid-filled container is discharged from the inside of the liquid-filled container through the discharge port of the discharge rod by operating the pressurized liquid supply source in the suction direction. How to make a container. According to claim 1 or 2, in the headspace forming step, by introducing a pressurized gas into the liquid-containing container, the liquid is discharged from the inside of the liquid-containing container through the discharge port of the discharge rod. The method for manufacturing a container containing a liquid according to the description. Any one of claims 1 to 3, further comprising a rod purging step of discharging liquid from the discharge port of the discharge rod inside the preform before and / or during molding into the liquid container. The method for manufacturing a container containing a liquid according to. The production of the liquid-containing container according to claim 4, wherein in the rod purging step, the entire amount of the liquid discharged from the inside of the liquid-containing container through the discharge port in the head space forming step performed last time is discharged from the discharge port. Method. The method for manufacturing a container containing a liquid according to claim 4 or 5, wherein in the rod purging step, the liquid is discharged from the discharge port of the discharge rod in the liquid. Any one of claims 1 to 6, further comprising an air discharge step of supplying a liquid to the inside of the preform prior to the liquid blow molding step to discharge the air inside the preform to the outside. The method for manufacturing a container containing a liquid according to. The liquid-containing container according to any one of claims 1 to 7, wherein the amount of liquid discharged from the inside of the liquid-containing container through the discharge port in the headspace forming step is equal to or less than the internal volume of the discharge path. Manufacturing method. Further comprising a rod stretching step of axially stretching the preform with a stretching rod during or prior to the liquid blow molding step.
The method for manufacturing a container containing a liquid according to any one of claims 1 to 8, wherein the discharge rod is the extension rod.

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