JPH0655419B2 - Method of manufacturing container with hanging tool - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a container such as an infusion bottle used as a drip container, which is formed by forming a hanging tool for hanging the container upside down.

[Prior Art] Molding of a container with a lifting device of this type requires a step of forming a lifting device in addition to injection molding of a parison and subsequent stretch blow molding, as in the case of molding a normal container. However, in order to reduce the cost of the container with a hanging tool, there is a demand for facilitating the manufacturing method thereof. On the other hand, since this type of container with a hanging tool is used for medical purposes such as a container for drip, the reliability of the hanging tool is required to be high. That is, if the container is detached from the hanger, a serious accident related to human life will be triggered.

The following proposals have been made regarding a method for manufacturing a container with a hanging tool of this type.

Japanese Unexamined Patent Publication No. 63-11324 discloses a manufacturing method in which a hanging device with a hole is integrally molded at the bottom of a parison at the stage of the injection molding process of pasolin.

On the other hand, in Japanese Patent Laid-Open No. 63-21804, stretch blow molding of a container is performed with the gate runner remaining at the bottom of the parison, and then the suspension is formed by another injection mold. A manufacturing method is disclosed in which the hole portion of the tool is inserted into the gate runner portion and the gate runner portion and the hanging tool are heat-welded.

[Problems to be Solved by the Invention] This type of container with a hanging tool is often used for medical purposes, and therefore it is necessary to make it easy to hang the hanging tool in case of an emergency. Is required to be a certain size or more. In this respect, when a hanger having a relatively large hole is integrally formed by injection molding of a parison as in the manufacturing method described in Japanese Patent Laid-Open No. 63-11324, the presence of this hanger simply causes the cylindrical parison to be formed. Is no longer molded, and its injection molding becomes more difficult than necessary. Further, in the case of the hot parison type in which the parison injection molding, blow molding, and eject operation are performed in one stage, the temperature distribution of the parison cannot be obtained due to the presence of a relatively large hanger, and the parison has an unbalanced temperature. The molded product also has a problem that the resin wall thickness varies.

On the other hand, the container with a hanging tool formed by the manufacturing method disclosed in Japanese Patent Laid-Open No. 63-218045 is inferior in terms of reliability with respect to the hanging tool. According to this manufacturing method, after inserting the hole of the suspender into the gate runner portion, the head of the gate runner portion projecting like a rivet from the suspender is welded to bond the two. In this case, if the container is suspended upside down, a large load is applied to the head portion of the rivet-shaped gate runner portion, and there is a high risk that the gate runner portion will fall off the suspending tool.

Moreover, according to this manufacturing method, it is necessary to perform the heat welding of the gate runner portion and the hanging device in a separate step, which causes a problem that the container with the hanging device cannot be manufactured at low cost.

Therefore, it is an object of the present invention that, in the parison injection molding process, by performing the injection molding conditions similar to those of a normal tubular parison, the quality of the container as the final product is not impaired, and the subsequent injection is performed. An object of the present invention is to provide a method of manufacturing a container with a hanging tool that can improve the reliability of the hanging tool by connecting the bottom part of the container and the hanging tool at the stage of the molding process.

[Means for Solving the Problem] The present invention relates to a method for manufacturing a container with a hanger having a hanger for hanging a container upside down on a bottom wall of the container, comprising: By integrally forming the projection for supporting the hanger on the wall, forming an engagement hole in the projection for supporting the hanger in the injection molding process or the temperature control process of the preform, and by stretch blow molding the preform. After molding the container, the container is arranged in a cavity mold having a cavity communicating with the engagement hole, and a ring-shaped hanger inserted into the engagement hole is injection-molded.

[Operation] In the present invention, first, the projection for supporting the hanger is integrally formed on the bottom wall of the parison at the stage of the injection molding process of the parison. The protrusion for supporting the hanger may be small, such as a gate runner portion, and therefore, the parison injection molding process can be performed under substantially the same conditions as those for molding a normal bottomed cylindrical parison.

Next, at the stage of the parison injection molding process or the temperature control process of the parison, the engagement holes are formed in the hanger support projections. When the engaging hole is formed in the injection molding process, the cavity mold may be provided with a pin for forming the engaging hole. Further, when the opening direction of the cavity mold and the direction of the pin are orthogonal to each other, this may be used as a slide pin, and the slide pin may be slid and separated from the parison before opening the cavity mold. Such engagement holes can also be realized by punching a parison in a relatively high temperature state. This punching process can be realized at a stage where the parison is maintained at a relatively high temperature, for example, at the injection molding stage after completion of injection molding, or at the temperature control stage.

After that, the parison is stretch blow-molded to be formed into a hollow container. After the stretch blow molding step, the hollow container is preferably placed in another injection molding die at an eject stage or the like. This injection molding die has a cavity that communicates with the engagement hole, and by filling the cavity with resin, it is possible to injection-mold a ring-shaped hanger that is inserted into the engagement hole. Becomes

[Example] Hereinafter, one example in which the present invention is applied to a method for manufacturing an infusion bottle with a hanging tool will be specifically described with reference to the drawings.

FIG. 2 shows an infusion solution bottle 10 with a hanger formed by the method of this example. In the figure, this infusion bottle 10 has a side wall 12 having a rectangular ring-shaped cross section, and its bottom wall 14 is provided with two leg portions 16 and 16 serving as a grounding surface when the infusion bottle 10 is in an upright state. Have These two legs 16,
In the area sandwiched by 16, the step surface 1 lower than the leg 16
8 is formed, and a concave portion 20 is provided in the center thereof so as to form a lower circular step surface. Then, at the center of the concave portion 20, the projection 22 for supporting the hanger is formed.
And the ring-shaped hanger 2 in a state of being integrally formed with the hanger support projection 22 and inserted into the engagement hole 24 formed in the hanger support projection 22.
6 is rotatably supported.

A method of manufacturing the infusion bottle 10 with the hanging tool will be described with reference to FIGS. 1 (A) to 1 (D).

FIG. 1A shows an injection molding process of the parison 30 as a preform of the infusion bottle 10.

In the injection molding process of the parison 30, one cavity mold 32 that can be opened and closed in the vertical direction in FIG. 1A to define the outer wall of the parison 30 and a core mold 34 that defines the inner wall of the parison 30. Is used. In addition, parison 30
Although not shown, the neck portion is formed by the core mold 34 and the neck mold (not shown). Also, this neck type makes the parison 30
Will be conveyed to each subsequent process. Then, the resin is introduced into the cavity 38 formed between the cavity mold 32 and the core mold 34 through the gate runner nozzle 36, so that the parison 30 is injection-molded. At this time, near the gate opening of the cavity mold 32,
A vertical rising portion is provided for molding the suspension supporting projection 22. During the injection molding of the parison 30, the suspension supporting projection 22 is molded integrally with the parison 30. Become. The hanger support protrusion 22 may be the gate runner portion itself.

Here, as the molding material of this parison 30, when the final product is an infusion bottle used for an infusion container or the like,
Polypropylene is the most suitable, but other thermoplastic resins such as polyethylene terephthalate (PET), polybutylene terephthalate, polyarylate and other thermoplastic polyester resins, or polyamide (nylon)
It is also possible to use a system resin, polyvinyl chloride, or the like.

According to the injection molding process of the parison 30 as described above, the size of the hanger support projection 22 should be large enough to allow post-processing of the engagement hole 24 for supporting the hanger 26. It is enough, and if it is about the size of the gate runner part, its purpose is sufficiently achieved. Therefore, the size of the hanger support projection 22 is extremely small as compared with the overall size of the tubular parison, which is almost the same as the molding conditions when molding a conventional ordinary bottomed cylindrical parison. The molding conditions are set, and the molding process of the parison 30 does not become complicated. Furthermore, even when compared with the manufacturing method disclosed in Japanese Patent Laid-Open No. 63-11324, the shape of the bottom portion of the parison 30 near the gate opening does not become complicated, so that the flow of resin in the parison is not deteriorated. It is also possible to prevent an adverse effect that uneven temperature of the parison 30 causes uneven thickness in the final product after blow molding.

FIG. 1 (B) shows the temperature control process of the parison 30. In the temperature control process of the parison 30, the heater 40 is provided along the stop position of the parison 30 or along the conveyance, and the parison 30 is set to the optimum temperature for the subsequent stretch blow molding.
Will be set. Here, in the method of the present embodiment, in this temperature adjusting step, the engaging hole 24 is punched in the projection 22 for supporting the hanger. For this purpose, a fixed piece 42 that comes into contact with one side surface of the hanging tool supporting projection 22 is fixedly arranged, and a movable piece having a pin 44a that is movable in the left-right direction in FIG. A piece 44 is provided. Then, by moving the movable piece 44 in the left direction, the engagement hole 24 penetrating from one side surface of the hanging tool supporting projection 22 to the other side surface is punched.

The size of the engagement hole 24 may be any size as long as it is commensurate with the diameter of the suspending tool 26 capable of withstanding the weight of the infusion bottle 10 to be suspended upside down. A diameter of 3 mm is recommended.

FIG. 1 (C) shows a stretch blow molding process of the parison 30. In order to perform this step, blow molds 50, 50 that can be opened and closed in the left-right direction in FIG. 3C are provided, and the neck portion is held above these two blow molds 50, 50 by a neck mold (not shown). The parison 30 is transported and then set inside the parison 30. Then, from above the parison 30, stretch rod 52
Is processed and moved, and the stretch piece 54 provided at the lower end thereof abuts the inner surface of the bottom wall 14 of the parison 30 to extend the parison 30 in the axial direction thereof, and at the same time, a pressurized fluid such as air is blown into the parison 30. by doing,
The parison 30 will be extended biaxially in the axial direction and the radial direction. As a result, as shown in FIG. 3, the infusion bottle 10 having the side wall 12 and the bottom wall 14 is blow-molded. This infusion bottle 10 has the above-mentioned hanging tool supporting projection 22 at the position of the recess 20 provided in the center of the bottom wall 14, and this hanging tool supporting projection 22 has an engaging hole 24 formed in the previous step.
Is provided.

FIG. 1 (D) shows an injection molding process of the hanger 26. This injection molding is performed by two injection molds 60a, 6 which can be opened and closed in the direction toward the front and back of the drawing of FIG.
0b (only one of which is shown in the figure) is provided, and the infusion bottle 1 is provided on the upper surfaces of the injection molds 60a and 60b.
A bottom wall accommodating notch 64 for accommodating the zero bottom wall 14 is formed. This ejection type 60a, 60b
The cavity 62 formed in the
It has a ring shape that communicates with the engagement hole 24 formed in the No. 2. A hot runner nozzle 66 that communicates with the center of the lower end of the cavity 62 is provided. By filling the resin inside the cavity 62 through the hot runner nozzle 66, injection molding of the hanging tool 26 is performed. . At this injection molding stage, the engagement hole 24 provided in the infusion bottle 10 is already solidified. Therefore, even if the hanger 26 is injection-molded with a resin having a melting point lower than that of the resin used for molding the infusion bottle 10 or the same material or the same kind of resin as the infusion bottle 10, the engagement hole 24 and the hanger 26 Since it is difficult to weld with, the hanger 26 can rotate with respect to the engagement hole 24 after the completion of injection molding.

In this way, after the suspension tool 26 is injection-molded, the suspension tool 26 is rotatable with respect to the engagement hole 24.
When 0 is satisfied, or when the infusion bottle 10 is packed in a box, as shown in FIG. 2, the suspending tool 26 is tilted toward the bottom wall 14 side so that it can be stored in the plane connecting the legs 16. Therefore, it is possible to realize a compact accommodation.

Other than the above-mentioned resin material as the injection-molding resin material of the hanging tool 26, low-density, medium-density or high-density polyethylene, ethylene-propylene copolymer and the like can be cited.

As described above, in the method of the present embodiment, the hanger 2 is formed by injection molding.
Since 6 is formed so as to be connected to the engagement hole 24, even if the infusion solution bottle 10 is filled with contents and hung upside down, the risk that the suspending tool 26 will separate from the infusion solution bottle 10 can be sufficiently reduced. In particular, the reliability of an infusion bottle used for medical purposes can be significantly improved. Further, particularly when it is used for medical purposes, it is necessary to secure a large size of a hole serving as a hanging portion of the hanging tool 26. Compared with a case where a hanger having such a large hole portion is used in the injection molding process of the parison 30, the injection molding after the blow molding does not cause any trouble in the molding of the infusion solution bottle 10 itself, and thus is relatively easy. It is possible to easily form the ring-shaped hanger 26 having a large hole.

Here, in this injection molding stage, when a resin is introduced into the cavity 62 to mold the hanger 26, the infusion bottle 10 is likely to be pushed upward by the resin pressure. Particularly, when the infusion bottle 10 is formed of a material having relatively high flexibility such as polypropylene, the side wall 12 thereof is easily deformed, and the bottom wall 14 is notched by the resin pressure so as to accommodate the bottom wall of the injection mold 60a, 60b. Part 6
It will be separated above 4. Therefore, in the method of the present embodiment, in order to prevent the bottom wall 14 of the infusion bottle 10 from rising, the push rod 68 for pressing the bottom wall 14 of the infusion bottle 10 from the inside toward the injection molds 60a, 60b. Is provided. This push rod 68
Alternatively, air may be blown into the infusion bottle 10, or the push rod 68 and blow air may be operated together.

Next, a preferred example of the injection molding apparatus used for the injection molding shown in FIG. 1 (D) will be described with reference to FIG.

As shown in FIGS. 4 to 7, this injection molding apparatus has an injection mold clamping cylinder 70 that drives the two injection molds 60a and 60b to open and close. The injection mold clamping cylinder 70 is attached to a movable plate 72, and the movable plate 72
Is movable on the slide guide plate 76 formed to project from the pressure receiving fixing plate 74 of the hot runner block 78 in the left-right direction in FIGS. 4 and 5. The cylinder rod 70a of the injection mold clamping cylinder 70 is fixed to one injection mold 60a on the side close to the cylinder 70.

As shown in FIG. 6, the two injectin molds 60a and 60b have guide rails 82 fixed to their side surfaces and are movable along guide grooves 84 formed on the side surfaces of the pressure receiving and fixing plate 74. Is. Further, a mold guide shaft 80 is provided to open and close the two injection molds 60a and 60b. This mold guide shaft 80
One end 80a is screwed and fixed to the movable plate 72, and the other end is screwed and fixed to the other injection mold 60b to which the cylinder rod 70a is not connected. The one injection mold 60a fixing the cylinder rod 70a is horizontally movable along the mold guide shaft 80.

The bottom wall storage notch 64 formed on the upper surface of the injection mold 60 abuts on the leg 16 and the recess 20 of the infusion bottle 10 as shown in FIG. 6, but as shown in FIG. In addition, it does not come into contact with the intermediate step surface 18 therebetween.

When injection-molding the suspending tool 26 in such an injection molding apparatus, first, the infusion bottle 1 held in the neck mold is used.
0 is conveyed to above the injection molding apparatus. After that, the hot runner block 78 and the hot runner nozzle 6
6 integrally moves upward, and in the bottom wall storing notch 64 formed on the upper surface of the hot runner nozzle 66, the infusion bottle 1
The bottom wall 14 of 0 is closely arranged. Furthermore, the push rod 6
When 8 is moved downward or blown air is blown into the infusion bottle 10, the bottom wall 14 thereof is pressed by the injection molds 60a and 60b. After this, the closing drive of the two injection molds 60a and 60b is started. 5 and 7 show the opened state of the two injection molds 60a, 60b,
The cylinder rod 70a of the injection mold clamping cylinder 70 is driven to extend in the upward direction of FIG. At this time, a half stroke S / 2 of the total stroke S of the cylinder rod 70a is directly used to move one injection mold 60a by a closing stroke, but the other half stroke S / is used. 2 is an injection mold clamping cylinder 70
The movable plate 72 to which is attached contributes to move backward on the slide guide plate 76 in the right direction in FIG. As a result, the other injection mold 60b moves by the closing stroke, and the closing drive of the two injection molds 60a and 60b is completed.

After that, the main nozzle (not shown) touches the hot runner block 78 to touch the hot runner block 7.
The resin is introduced into the cavity 62 formed in the two injection molds 60a and 60b through the runner 8 and the hot runner nozzle 66. As a result, the ring-shaped hanger 26 is injection-molded while being inserted into the engagement hole 24 formed in the hanger support projection 22. At this time, the bottom wall 1 of the infusion bottle 10
Since 4 is pressed against the injection molds 60a and 60b by the pressing rod 68 or blow air, it is possible to prevent the bottom wall 14 of the infusion bottle 10 from being lifted up by the resin pressure. As a result, with respect to the cavity 62 formed in the injection mold 60, the engagement hole 24 of the hanger support projection 22 can be always positioned so as to communicate with the cavity 62.

The present invention is not limited to the above embodiment,
Various modifications can be made within the scope of the present invention.

For example, in the manufacturing method of the above-mentioned embodiment, after the projection 22 for supporting the hanger is formed in the injection molding process of the parison 30, the engagement hole 24 is formed in the projection 22 in the temperature control process of the parison 30. However, it is not limited to this. For example, the engagement hole 24 can be formed at the time of injection molding of the parison 30. Alternatively, in this injection molding stage, the engagement hole 24 is formed by another member after injection molding.
It is also possible to punch.

EFFECTS OF THE INVENTION As described above, according to the method of the present invention, in the injection molding process of the parison, since it is sufficient to integrally form the projection for supporting the hanger having a relatively small volume on the bottom wall of the parison, it is possible to use a conventional It is possible to perform injection molding under conditions substantially equivalent to the injection molding conditions for the bottom cylindrical parison, and it is possible to reliably prevent the uneven thickness phenomenon of the final container due to the variation in the temperature distribution of the parison. After forming the projection for supporting the hanger, after forming the engaging hole in this projection and performing ordinary stretch blow molding, inject the hanger with a mold having a cavity communicating with this engaging hole. It is possible to manufacture a highly reliable container with a hanging tool that can be molded and can reliably prevent the lifting tool and the container from coming off even when used for medical purposes. In addition, since the hanger is formed in the injection molding process, it is possible to freely design a hanger with a shape that is easy to hang in an emergency. Even if such a hanger is molded, the container itself can be injection-molded. Alternatively, there is no adverse effect on the stretch blow molding process.

[Brief description of drawings]

1 (A) to 1 (D) are schematic explanatory views showing each step of the method for producing an infusion bottle with a hanging tool to which the present invention is applied, and FIG. 2 is a suspension formed by the production method in FIG. 3 is a schematic perspective view of the bottom wall portion of the infusion bottle with a tool, FIG. 3 is a schematic perspective view showing the bottom wall portion of the infusion bottle before the suspension tool is injection molded, and FIGS. FIG. 4 is a schematic sectional view of the injection molding apparatus in the mold clamping state, FIG. 5 is a schematic sectional view of the injection molding apparatus in the mold opening state, and FIG. FIG. 7 is a cross-sectional view of a mold at the time of injection molding, and FIG. 7 is a schematic plan view for explaining an injection mold in a mold open state. 10 ... Container (infusion bottle), 14 ... Bottom wall, 22 ... Lifting tool supporting projection, 24 ... Engagement hole, 26 ... Lifting tool, 30 ... Parison, 60 ... Injection molding injection mold , 62 ... cavity, 64 ... notch for storing bottom wall, 68 ... push rod.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Heijiro Sakurai 4586 Ko, Komoro-shi, Nagano 3 Nissei AS Machinery Co., Ltd. (56) References JP 63-11324 (JP, A) Special features Kai 63-21804 (JP, A)

Claims (1)

[Claims] 1. A method for manufacturing a container with a hanger having a hanger for hanging a container upside down in a bottom wall of the container, wherein a projection for supporting a hanger is provided on the bottom wall in an injection molding step of a preform. Integral molding, in the injection molding step or temperature control step of the preform, to form an engagement hole in the projection for supporting the hanging, after molding the container by stretch blow molding of the preform, the A method of manufacturing a container with a hanging tool, comprising: arranging the container in a cavity mold having a cavity communicating with the engaging hole, and injection-molding a ring-shaped hanging tool inserted into the engaging hole.