JP5004761B2 - Method for producing synthetic resin container and synthetic resin container - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a method for producing a synthetic resin container and a synthetic resin container. By combining an inner container part formed with a sheet or a film and an outer part by injection molding, the barrier property of the container by sheet molding and the like by injection molding A container having a composite function such as the strength of the container can be easily manufactured.

Synthetic resin containers are widely used for foods and the like. When it is necessary to prevent the contents from being spoiled or deteriorated, containers having gas barrier properties are used.
A container having such a gas barrier property can be manufactured by, for example, forming a laminate film or laminate sheet containing an ethylene vinyl acetate alcohol (EVOH) layer in the middle as a barrier resin by vacuum forming or pressure forming, or multilayer injection. It is manufactured by injecting a barrier resin in the middle by molding.

However, when a laminated sheet or the like is formed into a sheet, a cup-like container can be formed, but a container with legs, a thick container, a deep container, or the like cannot be formed.
On the other hand, in the case of multilayer injection molding, it is difficult to stably provide a barrier intermediate layer to the tip, and a special molding machine or mold structure must be used.

Therefore, the synthetic resin container of Patent Document 1 is a container having an inner portion made of a barrier laminate sheet and the like and an outer portion by injection molding, and the inner container is molded by vacuum molding or pressure molding, and then injected. It is mounted on a molding die and the outer portion is injection-molded, or conversely, the laminate sheet is brought into close contact with the inside of the injection-molded outer portion by vacuum molding.
Patent Document 2 also proposes a composite can comprising a metal inner layer formed by press molding and a plastic outer layer formed by injection molding using the metal inner layer as a core.

Japanese Patent Laid-Open No. 61-152556 JP 58-149255 A

However, a composite can having a metal inner layer as a core has problems such as restrictions on the shape of the container, and the container is not transparent and the contents cannot be easily seen.
On the other hand, when the outer container is molded by injection molding outside the inner part by vacuum molding or pressure molding, the inner part is mounted so as to cover the male protrusion, and the molten resin is inserted into the cavity between the female mold However, there are variations in the size and thickness of the inner portion, there is a problem that the molded product is not closely contacted with the male protrusion, and the molded product is wrinkled by a slight gap.
In addition, when the molten resin comes into contact with the inner part during injection molding, the barrier layer is exposed or damaged due to melting of the inner part due to heat and pressure, the barrier property is lowered, or the barrier property is lost. There is a problem.

  The present invention has been made in view of the above-mentioned problems and demands of the prior art, and has a barrier property of a sheet-molded container and strength of injection molding, and can be produced while preventing the occurrence of wrinkles. An object of the present invention is to provide a method for producing a container and a synthetic resin container.

The method for manufacturing a synthetic resin container according to claim 1 of the present invention for solving the problems of the prior art comprises an inner container portion made of a synthetic resin sheet or film and an injection molding on the outer side of the inner container portion. When manufacturing a synthetic resin container comprising an outer portion, a core provided with an undercut that is configured with a split mold and prevents the inner container portion from falling off is installed inside the inner container portion. The inner container portion is held in close contact or expanded, and then injection molded using a mold having a cavity in the outer portion.
According to this synthetic resin container manufacturing method, the inner container part is configured to have a split mold and provided with a core provided with an undercut, and the inner container part is held in close contact or expanded, It is designed to be injection-molded using a mold with a cavity in the outer part, and by expanding the split mold and keeping the inner container in close contact with the undercut while preventing the inner container from coming off, the dimensions of the inner container are achieved. Even if there is a variation, wrinkle generation is suppressed, and a synthetic resin container having a sheet molded container and an outer portion strength by injection molding can be easily manufactured. Furthermore, by using a split core, it becomes easy to attach the inner container part and release after molding, and to manufacture efficiently.

According to a second aspect of the present invention, there is provided a method for producing a synthetic resin container. In addition to the structure according to the first aspect, the synthetic resin container is injected from a gate into a mold having a cavity of the outer portion through a flow passage expanding portion. Thus, the inner container portion is prevented from being damaged by the resin.
According to this method of manufacturing a synthetic resin container, the inner container part is prevented from being damaged by the resin by being injected from the gate into the mold having the cavity of the outer part through the flow channel enlargement part. The heat and pressure of the injection-molded resin are relaxed by the path expanding portion and hit the inner container portion, so that the barrier property of the sheet-molded container can be secured.

Furthermore, in the method for manufacturing a synthetic resin container according to claim 3 of the present invention, in addition to the configuration according to claim 2, the flow passage enlarged portion is also used as a cavity formed in the outer portion. It is a feature.
According to this method for producing a synthetic resin container, the flow passage enlarged portion is also used as a cavity to be molded in the outer portion, and the inner container is simultaneously formed with the leg portion, the handle, the unevenness, the logo mark, the pattern, and the like. This makes it possible to manufacture a container made of synthetic resin while preventing damage to the part.

According to a fourth aspect of the present invention, in the synthetic resin container manufacturing method, in addition to the structure according to any one of the first to third aspects, the inner container portion is formed on a synthetic resin sheet or film as a barrier layer. The outer part is injection molded as a barrier multi-layer container having the above.
According to this synthetic resin container manufacturing method, the inner container portion is a barrier multilayer container having a barrier layer on a synthetic resin sheet or film, and has a barrier property and strength by injection molding. Can be easily manufactured.

Furthermore, in the method for producing a synthetic resin container according to claim 5 of the present invention, in addition to the configuration according to claim 4, the barrier layer is an EVOH layer as an inner container portion having an oxygen barrier property, The leg portion is injection-molded on the outer portion.
According to this method of manufacturing a synthetic resin container, the barrier layer is an EVOH layer and an oxygen barrier property inner container portion is formed, and the leg portion is injection-molded on the outer portion at the flow passage enlarged portion, and the oxygen barrier property It is possible to easily manufacture a container having a leg portion and strength by injection molding.

Moreover, in addition to the structure in any one of Claims 1-5, the manufacturing method of the synthetic resin container of Claim 6 of this invention is the outside after printing the inner container part on the outer surface. This is characterized in that the part is injection-molded.
According to this method for manufacturing a synthetic resin container, the inner container portion is printed on the outer surface, and then the outer portion is injection-molded. As a result, the ink can be prevented from being rubbed off and the ink can be prevented from being rubbed off and the range of use of the container and the degree of freedom of printing can be increased.

Furthermore, in the manufacturing method of the synthetic resin container according to claim 7 of the present invention, in addition to the structure according to any one of claims 1 to 6, the inner container portion is colored, and then the outer portion is It is characterized by being injection-molded with a different color from the inner container part.
According to this synthetic resin container manufacturing method, after the inner container portion is colored, the outer portion is injection-molded with a different color from the inner container portion, and the inner and outer colors are different. Can be easily manufactured, and it is also possible to easily manufacture a white container with a light shielding property.

Moreover, in addition to the structure in any one of Claims 1-7, the manufacturing method of the synthetic resin container of Claim 8 of this invention adds the label to the outer surface after attaching the label to the outer surface. This is characterized in that the part is injection-molded.
According to this method of manufacturing a synthetic resin container, the inner container part is made by injection-molding the outer part after affixing a label to the outer surface, and a label is created separately from the molding of the inner container. In addition, it can be affixed to prevent the label from being damaged, and the degree of freedom in decoration and design can be further increased.

Furthermore, the manufacturing method of the synthetic resin container according to claim 9 of the present invention is such that, in addition to the configuration according to any one of claims 1 to 8, a recess is formed in the core of the mold that holds the inner container part. The stack ribs are protruded from the inner container portion by resin pressure by injection molding of the outer portion.
According to this method for manufacturing a synthetic resin container, a recess is formed in a core of a mold that holds an inner container part, and a rib for stacking is projected to the inner container part by resin pressure by injection molding of an outer part. The rib can be easily protruded inward simply by forming a recess in the mold core, and the stacking rib can be easily formed without the need to align the inner container. .

Moreover, in addition to the structure in any one of Claims 1-9, the manufacturing method of the synthetic resin container of Claim 10 of this invention adds the end surface of the synthetic resin sheet or film of the said inner container part, The outer part is covered with resin by injection molding.
According to this method for producing a synthetic resin container, the end surface of the synthetic resin sheet or film in the inner container portion is covered with resin by injection molding of the outer portion, and from the end surface during boil or retort sterilization. In particular, it is possible to prevent the deterioration of the oxygen barrier property due to the EVOH layer regardless of the sterilization method.

Furthermore, the synthetic resin container according to claim 11 of the present invention is manufactured by the method for manufacturing a synthetic resin container according to any one of claims 1 to 10.
According to this synthetic resin container, it is manufactured by the method for manufacturing a synthetic resin container according to any one of claims 1 to 10, and the inner container of sheet molding is free of wrinkles, barrier properties, etc. And a synthetic resin container having the strength of the outer portion by injection molding and the like.

  According to the method for manufacturing a synthetic resin container according to claim 1 of the present invention, an inner container portion made of a synthetic resin sheet or film, and an outer portion formed by injection molding outside the inner container portion. When manufacturing synthetic resin containers that are equipped with, the inner container part is attached to the inside of the inner container part with a core made of a split mold and provided with an undercut so as to hold the inner container part in close contact or spread After that, injection molding was performed using a mold having a cavity in the outer part, so that the inner container could be brought into close contact by expanding the split mold while preventing the inner container part from coming off with an undercut. Even if there are variations in the dimensions of the container, it is possible to easily produce a synthetic resin container that suppresses the generation of wrinkles and has the strength of the outer part by sheet molding and injection molding. Furthermore, by using a split core, it becomes easy to mount the inner container part or release the molded product, and it can be manufactured efficiently.

  According to the method for manufacturing a synthetic resin container according to claim 2 of the present invention, the inner container part is damaged by the resin injected into the mold having the cavity of the outer part from the gate through the flow channel enlargement part. Therefore, the heat and pressure of the injection molding resin is relaxed by the flow path expanding part and hits the inner container part, and it is possible to prevent damage to the sheet molding container and to secure barrier properties and the like. it can.

  Furthermore, according to the method for manufacturing a synthetic resin container according to claim 3 of the present invention, since the flow passage expanding portion is also used as a cavity formed in the outer portion, for example, a leg portion formed in the outer portion, By using a cavity such as a handle, unevenness, logo mark, or pattern as a flow path enlarged portion, it is possible to manufacture a synthetic resin container while preventing the inner container portion from being damaged at the same time as forming the outer portion.

  According to the method for manufacturing a synthetic resin container according to claim 4 of the present invention, the inner container portion is a barrier multilayer container having a barrier layer on a synthetic resin sheet or film. And the container provided with the intensity | strength by injection molding can be manufactured easily.

  Furthermore, according to the method for manufacturing a synthetic resin container according to claim 5 of the present invention, the barrier layer is used as an EVOH layer to form an oxygen-barrier inner container portion, and the leg portion is injection-molded at the outer portion of the flow path expanding portion. Since it did in this way, the container which has oxygen barrier property, was equipped with the leg part, and was equipped with the intensity | strength by injection molding can be manufactured easily.

  According to the method for manufacturing a synthetic resin container according to claim 6 of the present invention, since the inner container portion is printed on the outer surface and then the outer portion is injection-molded, the printed surface is on the outer side. It is possible to prevent the solvent odor from being exposed to the outside and to prevent the ink from rubbing and peeling off, thereby increasing the use range of the container and the degree of freedom of printing.

  Furthermore, according to the method for manufacturing a synthetic resin container according to claim 7 of the present invention, after the inner container portion is colored, the outer portion is injection-molded with a different color from the inner container portion. Containers with different outer colors can be easily manufactured. For example, a white container with a light-shielding property can be easily manufactured.

  According to the method for manufacturing a synthetic resin container according to claim 8 of the present invention, since the outer container is injection molded after the label is attached to the outer surface, the inner container is molded. Separately, a label can be prepared and affixed, which can prevent the label from being damaged, and can further increase the degree of freedom in decoration and design.

  Furthermore, according to the method for manufacturing a synthetic resin container according to claim 9 of the present invention, the recess is formed in the core of the mold that holds the inner container portion, and the rib for stacking is performed by resin pressure by injection molding of the outer portion. Since the rib is projected to the inner container part, it is possible to easily protrude the rib on the inside just by forming a recess in the mold core, and there is no need to align the inner container part. Ribs can be formed.

  Moreover, according to the method for manufacturing a synthetic resin container according to claim 10 of the present invention, the end surface of the synthetic resin sheet or film of the inner container portion is covered with the resin by injection molding of the outer portion. It is possible to prevent moisture and the like from being absorbed from the end face during boil and retort sterilization, and in particular, it is possible to prevent a decrease in oxygen barrier properties due to the EVOH layer regardless of the sterilization method.

  Furthermore, according to the synthetic resin container according to claim 11 of the present invention, since it is manufactured by the method for manufacturing a synthetic resin container according to any one of claims 1 to 10, an inner container for sheet molding It is possible to make a synthetic resin container having no wrinkles and the like, having barrier properties and the like, and having strength of an outer portion by injection molding.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, a synthetic resin container 10 to which the manufacturing method of the present invention is applied is formed by injection molding on an inner container part 11 made of a synthetic resin sheet or film and on the outer side of the inner container part 11. The outer portion 12 includes an outer container portion 12a that covers the entire outer side of the inner container portion 11 and a leg portion 12b that is integrally molded. It consists of a container with legs.

  The inner container part 11 is, for example, a laminated film in which upper and lower surface layers 13a and 13a are made of a polypropylene film as a synthetic resin sheet 13, and an intermediate layer 13b of an ethylene vinyl acetate alcohol copolymer film (EVOH) is laminated in the middle. 13 is used to provide oxygen barrier properties to prevent permeation of oxygen by the ethylene vinyl acetate alcohol copolymer film of the intermediate layer 13b.

The inner container part 11 is manufactured by placing the laminate film 13 on a molding die (not shown) and molding it into a shape that conforms to the concave shape formed in the mold by vacuum molding or pressure molding. As shown, a conical opening 11a is formed at the top, has a substantially spherical bottom 11c via an intermediate cylindrical portion 11b, and a ring-shaped flange 11d is formed at the top. Between the flange part 11d and the conical opening 11a, an undercut part 11e whose upper end is squeezed inward is formed.
Such an inner container part 11 can be easily formed into a barrier multilayer container having gas barrier properties by using a synthetic resin film 13 on which a gas barrier resin layer 13b is laminated in advance.

  On the other hand, the inner container portion 11 is molded so as to conform to the shape of the concave portion of the mold by a sheet molding method, so that a container with a leg portion and the like cannot be molded, and the shape that can be molded is limited. In comparison, the strength is low, the dimensions and thickness vary, and the outer peripheral portion of the synthetic resin sheet 13 is cut after molding, so that the flange 11d exposes the end surfaces of the laminated sheets 13a, 13b, and 13a. It is in a state.

In the synthetic resin container 10, the outer part 12 is molded and integrated with the inner container part 11 by injection molding in the next step.
In this injection molding step, for example, as shown in FIGS. 2 and 3, a pair of male and female injection molds 14 and 15 are used, arranged inside the inner container part 11 and mounted with the inner container part 11. A split core 14 that is a male mold that is held in a close contact state or a spread state, and an outer mold 15 that is a female mold in which a cavity of the outer portion 12 is formed.

  The split core 14 constituting the male mold is divided into three split molds 14a, 14b, 14c as shown in FIGS. 2 and 3, for example, taking into account dimensional tolerance due to sheet molding of the inner container part 11. The product dimensions of the synthetic resin container 10 are obtained in a combined state, and the inner container part 11 can be held on the core 14 in a close contact state or in a state of being expanded.

Further, when the inner container part 11 is brought into close contact with the core 14 so as to spread out, the inner container can be held without being pulled out by the shape of the conical opening 11a of the inner container part 11 or the like. An undercut 14d corresponding to the undercut portion 11e of the portion 11 is formed.
By using the core 14 having such an undercut 14d and a divided structure, even when the inner container part 11 is mounted so as to cover the core 14, it can be easily mounted by reducing the diameter of the core 14 In addition, the inner container part 11 is brought into close contact with the core 14 having an enlarged diameter, so that generation of wrinkles due to injection molding can be prevented. After the injection molding, the diameter of the molded product 10 is reduced from the core 14 by reducing the diameter. It can be easily removed by molding.

The outer mold 15 that is a female mold that forms the cavity of the outer portion 12 outside the inner container portion 11 that is mounted on the core 14 has an outer container portion 12a and a leg portion 12b that cover the inner container portion 11. In addition, the cavities 15a and 15b are formed, and here, a cavity 15c for a flange covering portion for covering the end surface of the flange portion 11d of the inner container portion 11 by injection molding is formed.
As shown in FIG. 3, the outer mold 15 forming the cavities 15a to 15c of the outer portion 12 is divided at the flange covering portion and the lower end of the leg portion, and a leg core 15d is provided for the leg portion 12b. .

Further, the injection molds 14 and 15 are provided with a gate 16 at the bottom of the outer mold 15 so that molten resin for injection molding is injected from the gate 16 through a leg cavity 15b. The inner container portion 11 is not directly exposed to the molten resin for injection molding from the gate 16, and the leg cavity 15 b is used as the molten resin flow passage enlarged portion 17, and the small diameter gate 16 is tapered. Heat and pressure are relaxed by the flow path expanding portion 17 expanded in a shape, and the molten resin for injection molding is injected so as to be in contact with the outer surface of the substantially spherical bottom portion 11 c of the inner container portion 11.
Here, two gates 16 are formed at the bottom of the outer mold 15, and the molten resin for injection molding is uniformly distributed from both sides through the leg cavity 15 b constituting the flow path expanding portion 17. The portion 11 is injected so as to be in contact with the outer surface of the substantially spherical bottom portion 11c.

Further, in the injection molds 14 and 15, a recess 18 is formed in the core 14 that holds the inner container portion 11, and a rib 19 corresponding to the recess 18 is formed by the resin pressure by injection molding of the outer portion 12. The bottom end of the synthetic resin container 10 can be supported by forming a plurality of ribs 19 at a certain height from the bottom part 11c, thereby allowing the synthetic resin container to support the lower end of the leg part 12b. When 10 are stacked one on top of another, they are not in close contact with each other and can maintain a predetermined interval.
In this way, in the sheet molding of the inner container part 11, the rib 19 is not formed, and when the outer part 12 is injection molded, the concave part 18 is formed in the core 14 and the inner container part 11 is pressed by the pressure of the resin for injection molding. Since the rib 19 is formed, it is not necessary to align the inner container part 11 when the inner container part 11 is attached to the core 14, and the rib 19 can be easily formed for stacking.
The stacking ribs 19 are formed, for example, at approximately six circumferentially spaced intervals, so that the center axis can be aligned with the substantially spherical bottom portion 11c without tilting the disc-shaped leg portion 12b. .
The stacking ribs 19 may be formed at least at three or more locations.

  The injection molding of the outer portion 12 using the injection molding dies 14 and 15 is performed after the inner container portion 11 molded by sheet molding is mounted in a state where the core 14 constituted by a split mold is reduced in diameter. The diameter of the core 14 is increased so that the undercut 14d of the core 14 is fitted to the undercut portion 11e of the inner container part 11, and the inner container part 11 is held in a state where the inner container part 11 is in close contact with the product and is expanded.

The core 14 holding the inner container part 11 is set in the outer mold 15, and the cavities 15 a and 15 b of the outer part 12 are formed outside the inner container part 11, and the cavity 15 c of the flange covering part is formed.
Then, resin for injection molding is injected from the two gates 16 formed on the bottom of the outer mold 15.
Then, the molten resin injected from the two gates 16 flows into the conical side surface flow path by the leg cavities 15b constituting the flow path expanding portion 17, and the heat and pressure of the molten resin are alleviated. The inner container part 11 is injected from the bottom of the cavity 15b of the outer part 12 through the cavity 15a of the upper outer container part 12a into the cavity 15c of the flange covering part.
Thereby, the outer container part 12a and the leg part 12b are integrally formed outside the inner container part 11.

And since the shape | molded synthetic resin container 10 makes the core 14 closely_contact | adhere to the inner side container part 11, it can prevent generation | occurrence | production of a wrinkle and can obtain a molded article with sufficient quality.
Furthermore, since the inner container part 11 is pre-molded by sheet molding and then attached to the core 14 and the outer part 12 is injection molded, for example, the inner container part 11 having gas barrier properties is simply molded using the laminate sheet 13. The strength and shape that cannot be obtained by sheet molding can be easily and integrally formed by injection molding of the outer portion 12, and the gas barrier legged container 10 is compared with the molding method by the multilayer injection molding method. It can be easily molded.

Further, the end surface of the flange portion 11d of the inner container portion 11 is covered with the injection resin injected into the cavity 15c of the flange covering portion, and the end surface of the intermediate layer 13b of the laminate sheet 13 is also covered with the injection resin.
Thereby, in order to provide gas barrier properties, even when the EVOH layer is used as the intermediate layer 13b in the laminate sheet 13, for example, moisture absorption from the end face of the flange portion 11d can be prevented, and the synthetic resin container 10 is filled with the contents. Thereafter, even when sterilization with boil or retort sterilization is performed, a decrease in barrier properties can be prevented, and the selectivity of the sterilization method can be expanded.

Further, in the method of manufacturing the synthetic resin container 10, the recess 18 is formed in the core 14 to which the inner container part 11 is attached, and the inner container part 11 is inflated with the pressure of the injection molding resin that forms the outer part 12. Thus, the protruding rib 19 can be formed.
Thereby, by using the protruding ribs 19 for stacking, the inner container part 11 and the core 14 do not need to be aligned, and can be easily molded, thereby preventing the containers 10 from being closely adhered (blocking). be able to.

After the outer portion 12 is injection-molded outside the inner container portion 11 in this way, it is cooled and cured, and the mold is opened to release the molded product 10 and take it out.
At the time of this mold release, by reducing the diameter of the split core 14, a gap can be formed between the inner container part 11 and the core 14 in a close contact state, and the molded product 10 can be easily separated from the core 14. Can be typed.

  As described above in detail with the embodiment, according to the method for manufacturing the synthetic resin container 10, the inner container part 11 made of the synthetic resin sheet 13 or film and the outer side of the inner container part 11. In the case of manufacturing a synthetic resin container 10 having an outer portion 12 formed by injection molding, a core 14 formed of a split mold and provided with an undercut 14d is provided inside the inner container portion 11. After mounting and holding the inner container part 11 in close contact or expanded, injection molding is performed using the mold 15 having the cavities 15a to 15d of the outer part 12, so that the inner container is formed by the undercut 14d. The inner core 11 can be brought into close contact by spreading the split-type core 14 in a state in which the portion 11 is prevented from being pulled out. Raw the synthetic resin container 10 with a like intensity of the outer portion 12 can be easily manufactured by injection molding the container 11 of the sheet forming is suppressed. Furthermore, by using the split core 14, it becomes easy to mount the inner container part 11 or release the molded product 10, so that it can be efficiently manufactured.

  Further, according to the method for manufacturing the synthetic resin container 10, the resin is injected into the mold 15 having the cavities 15a to 15d of the outer portion 12 from the gate 16 through the flow channel enlargement portion 17 (15b), and the inner side by the resin. Since the container part 11 is prevented from being damaged, the heat and pressure of the injection molding resin is relaxed by the flow path expanding part 17 and hits the inner container part 11 to prevent the sheet forming container 11 from being damaged. Barrier properties and the like can be ensured.

  Further, according to the method for manufacturing the synthetic resin container 10, the flow path enlarged portion 17 is also used as the leg cavity 15b to be molded on the outer portion 12, so that the leg portion 12b of the outer portion 12 is molded. At the same time, it is possible to manufacture the synthetic resin container 10 by preventing the inner container part 11 from being damaged.

  Further, according to the method for manufacturing the synthetic resin container 10, the inner container part 11 is the barrier multilayered container 11 having the barrier layer 13b on the synthetic resin sheet 13 or film. The container 10 having strength by injection molding can be easily manufactured.

  Further, according to the method for manufacturing the synthetic resin container 10, the barrier layer is the EVOH layer 13 b to form the oxygen-barrier inner container part 11, and the leg part 12 b is injection-molded on the outer part 12 by the flow path expanding part 17. Therefore, the container 10 having oxygen barrier properties and having the leg portions 12b and strength by injection molding can be easily manufactured.

  Further, according to the method for manufacturing the synthetic resin container 10, the recess 18 is formed in the core 14 of the mold that holds the inner container part 11, and the stack rib 19 is formed by resin pressure by injection molding of the outer part 12. Since the inner container portion 11 protrudes, the rib 19 can be easily protruded inward simply by forming the recess 18 in the core 14 of the mold, and the inner container portion 11 does not need to be aligned. The ribs 19 for stacking can be easily formed.

  Further, according to the method for manufacturing the synthetic resin container 10, the end surface of the synthetic resin sheet 13 or the film of the inner container part 11 is covered with the resin by the injection molding of the outer part 12, so that the boil or the retort It is possible to prevent moisture and the like from being absorbed from the end face during sterilization, and in particular, it is possible to prevent the oxygen barrier property from being lowered by the EVOH layer 13b regardless of the sterilization method.

Next, another embodiment of the present invention will be described with reference to FIG. 4, but the same parts as those in the above-described embodiments of FIGS. .
In the method of manufacturing a synthetic resin container according to this embodiment, the shape of the inner container portion 21 of the synthetic resin container 20 to be manufactured is different, and the body portion 21a and the bottom portion 21b are substantially elliptical and smooth. And a flange portion 21d is formed at the upper end through an undercut portion 21c to provide an opening portion 21e.
The outer portion 22 provided outside the inner container portion 21 is configured such that an outer container portion 22a is provided so as to cover the entire inner container portion 21, and a conical leg portion 22b is integrally provided. ing.

Such a synthetic resin container 20 is also constituted by split molds using injection molds 14 and 15 after the inner container part 21 is formed in advance using a laminate sheet 13 or the like which is a synthetic resin sheet. It can be easily molded by injection molding in the same manner as the embodiment already described in combination with the outer mold 15 which is attached to the core 14 and held in close contact or expanded and combined with the outer portion 15 formed with the cavities. In addition, the same operations and effects as in the above embodiment can be obtained.
In this synthetic resin container 20, as shown in FIG. 4 (a), the undercut portion 21c and the body portion 21a of the inner container portion 21 can be supported when they are overlapped. It is not necessary to form a rib that is used to inflate the inner container portion 21.

  The synthetic resin container is not limited to the container with legs of the above two embodiments, but the shape of the inner container part and the shape of the outer part, such as a cup-shaped container, a bottle-shaped container, a glass-shaped container, and a can-shaped container. Different shapes may be used, and the outer portion is not necessarily provided as a shape covering the entire inner container, but may be configured with a handle, unevenness, logo mark, pattern, etc., or a combination of these, or other shapes Also good.

  In addition, when the outer portion is injection-molded, the resin injected from the gate is applied to the inner container portion by relaxing the heat and pressure through the flow passage expanding portion. In addition to using the cavity, it can be a handle, or a molded part may be provided with a flow channel enlarged part as an unnecessary part and cut off after molding.

  Furthermore, in the method for producing a synthetic resin container according to the present invention, after the outer surface of the inner container portion is printed, the outer portion may be injection-molded. It is possible to manufacture a synthetic resin container that is not exposed to the outside and is covered with the outer part so that the solvent odor is not exposed to the outside, and the printed surface can be prevented from being scraped off and rubbed. The degree of freedom can be increased.

  Furthermore, in the method for manufacturing a synthetic resin container according to the present invention, after the inner container portion is colored, the outer portion can be injection-molded with a different color from the inner container portion. Containers of different colors can be easily manufactured. For example, a synthetic resin container or the like in which the outer portion is black or titanium having light-shielding properties and the inner side is white can be easily manufactured.

  Further, according to the method for manufacturing a synthetic resin container of the present invention, the inner container portion can be injection-molded after the label is attached to the outer surface, and separately from the molding of the inner container. A label can be created and affixed, and the label can be prevented from being damaged. By using the label, the decorativeness and design are more freedom than when directly printing or coloring. The degree can be increased.

  The method for manufacturing a synthetic resin container according to the present invention is not limited to a case where a plurality of the inventions described in each claim are combined as in the above-described embodiment, but independently in the scope described in each claim. It can also be set as the structure which carried out.

It is a half cut sectional view of the inner side container part concerning the synthetic resin container to which one embodiment of the manufacturing method of the synthetic resin container of this invention is applied, a half cut sectional view of the whole container, and an enlarged sectional view of the flange part. It is sectional drawing of the diameter-reduced state of the core for injection molding concerning one Embodiment of the manufacturing method of the synthetic resin containers of this invention, and sectional drawing of a diameter-expanded state. It is sectional drawing of the metal mold | die for injection molding concerning one Embodiment of the manufacturing method of the synthetic resin containers of this invention. It is a half cut sectional view of the inner side container part concerning the synthetic resin container to which other one Embodiment of the manufacturing method of the synthetic resin container of this invention is applied, and an expanded sectional view of a flange part.

Explanation of symbols

10, 20 Synthetic resin containers 11, 21 Inner container part 11a Conical opening 11b Intermediate cylindrical part 11c Substantially spherical bottom part 11d Flange part 11e Undercut parts 12, 22 Outer part 12a Outer container part 12b Leg part 13 Synthetic resin sheet (laminate film)
13a Upper and lower surface layers 13b Intermediate layer (oxygen barrier layer)
14 Core (mold for injection molding)
14a to 14c Split mold 14d Undercut 15 Outer mold (mold for injection molding)
15a Cavity 15b of outer container part 15c cavity of leg part 15c cavity 15d of flange covering part Core 16 for leg part Gate 17 Flow path enlarged part 18 Recessed part 19 Rib for stacking

Claims (11)

When manufacturing a synthetic resin container comprising an inner container portion made of a synthetic resin sheet or film and an outer portion formed by injection molding outside the inner container portion,
Inside the inner container part, a core formed with a split mold and provided with an undercut that prevents the inner container part from falling off is attached and the inner container part is held in close contact or expanded, and then the outer part is A method for producing a synthetic resin container, wherein a mold having a cavity is injection-molded.   2. The synthetic resin container according to claim 1, wherein the inner container part is prevented from being damaged by the resin by being injected from the gate into the mold including the cavity of the outer part through the flow path expanding part. Manufacturing method.   3. The method for manufacturing a synthetic resin container according to claim 2, wherein the flow passage enlarged portion is also used as a cavity formed in the outer portion.   The synthetic resin according to any one of claims 1 to 3, wherein the inner container portion is formed by injection molding the outer portion as a barrier multilayer container having a barrier layer on a synthetic resin sheet or film. A method for producing a container.   The synthetic resin container according to claim 4, wherein the barrier layer is an EVOH layer to form an oxygen-barrier inner container part, and a leg part is injection-molded at an outer part of the flow path enlarged part. Method.   The method for producing a synthetic resin container according to any one of claims 1 to 5, wherein the inner container portion is printed on the outer surface, and then the outer portion is injection-molded.   The synthetic resin container according to any one of claims 1 to 6, wherein the inner container portion is colored and then the outer portion is injection-molded with a different color from the inner container portion. Production method.   The method for producing a synthetic resin container according to any one of claims 1 to 7, wherein the inner container portion is formed by injection molding the outer portion after a label is attached to the outer surface.   9. A concave portion is formed in a core of a mold for holding the inner container portion, and a rib for stacking is protruded from the inner container portion by resin pressure by injection molding of an outer portion. A method for producing a synthetic resin container according to any one of the above. The synthetic resin container according to any one of claims 1 to 9, wherein an end surface of the synthetic resin sheet or film of the inner container part is covered with a resin by injection molding of an outer part. Method.   A synthetic resin container manufactured by the method for manufacturing a synthetic resin container according to any one of claims 1 to 10.

Images