JP7404628B2 - multiple containers - Google Patents

Description

The present invention relates to multiple containers.

BACKGROUND ART A multi-layered container is known that attempts to realize a heat-retaining function for contents by forming a gap between an inner container and an outer container that are stacked in a peelable manner (for example, Patent Document 1).

Japanese Patent Application Publication No. 2005-47593

In the multiple container described in Patent Document 1, in order to separate the outer container and the inner container to form a gap, at least one of the inner surface of the body of the outer container and the outer surface of the body of the inner container is A large number of protrusions are formed. For this reason, in the multiplex container described in Patent Document 1, at least one of the outer container and the inner container has a complicated shape and structure, and the amount of resin needs to be increased by the amount of ridges formed, which increases the cost of the resin material. may increase.

Furthermore, in the multiplex container described in Patent Document 1, the protrusion formed on at least one of the inner surface of the body of the outer container and the outer surface of the body of the inner container is in close contact with the surface opposite to the protrusion. , the outer container and the inner container are difficult to separate, and even if they do, it is only a partial separation. Therefore, the multi-layered container described in Patent Document 1 has room for improvement in stably forming voids large enough to achieve a heat-retaining function for the contents.

The present invention has been made in view of the above-mentioned circumstances, and an example of an object to be solved is to solve the above-mentioned problems. That is, one example of the problem of the present invention is to provide a multi-layered container that can simply and stably realize the function of keeping the contents warm.

The multi-layered container according to the present invention is formed by stretch-blowing an inner preform corresponding to an inner container that can be filled with contents and an outer preform corresponding to an outer container, and the inner preform and the inner preform are formed by stretch-blowing. This is a bottle-shaped multi-layered container in which the outer container encapsulating a container is removably stacked, the outer container and the inner container are molded using a polyester resin, and the outer container and the inner container are separated from each other. In between, there is provided a peeling part made of a release agent that is solid at room temperature, the melting point of the release agent is 30°C or more and 70°C or less, and the peeling part is formed by stretching the outer preform by the stretching blow. the inner surface of a portion of the stretched portion of the inner preform that corresponds to the shoulder and body excluding the bottom of the outer container, and the shoulder and body of the stretched portion of the inner preform excluding the bottom of the inner container The multi-layered container is provided by applying the molten release agent to at least one outer surface of a portion corresponding to A gap is formed between the inner container and the outer container by peeling off the shoulder and body of the inner container through the part, and when the inner container is filled with the contents, the gap is maintained .

Preferably, in the multi-layered container , the peeling portion is formed at a mouth portion of the outer container corresponding to a non-stretched portion of the outer preform that is not stretched even by the stretching blow, and at the non-stretched portion of the inner preform. The opening of the outer container is provided with an outside air introduction hole that is not provided between the opening of the corresponding inner container and can introduce outside air between the outer container and the inner container.

Preferably, in the multiple container, the release agent is paraffin wax.

The method for manufacturing a multiple container according to the present invention includes stretch-blowing an inner preform corresponding to an inner container capable of being filled with contents and an outer preform corresponding to an outer container. A method for manufacturing a multiple container, which molds a bottle-shaped multiple container in which the outer container enclosing a container is removably laminated, the outer container and the inner container being molded using a polyester resin; , a peeling part made of a peeling agent that is solid at room temperature is provided between the outer container and the inner container, the melting point of the peeling agent is 30°C or more and 70°C or less, and the peeling part is The inner surface of a portion of the stretched portion of the outer preform that is stretched by the stretch blow and corresponds to the shoulder and body portions excluding the bottom of the outer container, and the content of the stretched portion of the inner preform. It is provided by applying the melted release agent to at least one of the outer surfaces of the portions corresponding to the shoulders and body excluding the bottom of the container, and the multiple containers are formed by heat shrinking after molding. By peeling off the shoulder and body of the inner container from the shoulder and body of the inner container via the peeling part, a gap is formed between the inner container and the outer container, and the contents are removed from the inner container. The void is maintained in a filled state.

The multiple container according to the present invention can easily and stably realize the function of keeping the contents warm.

1 is a diagram schematically showing a longitudinal section of a multiplex container according to Embodiment 1. FIG. 1 is a diagram schematically showing a preform for manufacturing multiple containers according to Embodiment 1. FIG. FIG. 3 is a diagram schematically showing a longitudinal section of a multiplex container according to Embodiment 2.

Embodiments of the present invention will be described below with reference to the drawings.

In this embodiment, the direction along the central axis Z of the multiple containers 1 having a bottle shape is also referred to as the "axial direction", and the direction in which the multiple containers 1 rotate around the central axis Z as the rotation axis is also referred to as the "circumferential direction". The direction perpendicular to the central axis Z of the multiple containers 1 is also referred to as the "radial direction." Furthermore, in this embodiment, the axial direction from the mouth 3 to the bottom 6 of the multiple containers 1 is also referred to as "downward", and the axial direction from the bottom 6 to the mouth 3 of the multiple containers 1 is also referred to as "up". In addition, in this embodiment, a cross section of the multiple containers 1 taken along a plane along the central axis Z of the multiple containers 1 is also referred to as a "longitudinal section", and a cross section of the multiple containers 1 taken along a plane perpendicular to the central axis Z of the multiple containers 1 is referred to as a "longitudinal section". The cut cross section is also referred to as a "cross section."

[Embodiment 1]
FIG. 1 is a diagram schematically showing a longitudinal section of a multiple container 1 according to the first embodiment. FIG. 2 is a diagram schematically showing preforms 100 and 200 for manufacturing the multiple containers 1 according to the first embodiment. Note that FIG. 1 shows the multiple container 1 after the inner surface of the outer container 10 and the outer surface of the inner container 20 have been separated.

The multiple container 1 is a bottle-shaped container. As shown in FIG. 1, the multiple container 1 has a mouth portion 3 which is one end of the multiple container 1 and has a spout 21 for pouring out the contents, and a bottom portion 6 which is the other end of the multiple container 1 and has a grounding portion. , a shoulder portion 4 extending downward from the mouth portion 3 while expanding outward in the radial direction, and a body portion 5 extending downward from the shoulder portion 4 and connected to the bottom portion 6.

The multiple container 1 includes a bottle-shaped outer container 10 that forms the outer shell of the multiple container 1 and houses an inner container 20, and an inner container 20 that stores the contents and has a shape that conforms to the inner surface of the outer container 10. Be prepared. The multiple container 1 is a heat-insulating bottle in which the inner surface of an outer container 10 and the outer surface of an inner container 20 are laminated in a separable manner. The multiple container 1 may be a heat-resistant bottle applicable to hot filling in which the contents are heated to a high temperature and filled. The contents of the multiplex container 1 may be high-temperature contents such as hot drinks, or low-temperature contents such as cold drinks or frozen desserts.

The outer container 10 and the inner container 20 are containers made of synthetic resin, and are manufactured by blow molding. Preferably, the outer container 10 and the inner container 20 are manufactured by biaxial stretch blow molding using tubular preforms 100 and 200, such as test tube shapes, as shown in FIG. Preforms 100 and 200 are manufactured in advance by injection molding or the like. The preforms 100 and 200 correspond to a mouth part 3, a non-stretched part M which is a part that is not stretched by biaxial stretch blow molding, and a shoulder part 4, a body part 5 and a bottom part 6, which are parts that are not stretched by biaxial stretch blow molding. It is composed of a stretched portion N, which is a portion stretched by.

As shown in FIG. 2, the outer container 10 and the inner container 20 are constructed by inserting a preform 200 corresponding to the inner container 20 into a preform 100 corresponding to the outer container 10 and stacking the preform 100. and 200 simultaneously by biaxial blow molding. Alternatively, the outer container 10 and the inner container 20 may be formed by biaxially stretching blow molding the preform 100 corresponding to the outer container 10 and then biaxially stretching blow molding the preform 200 for the inner container 20 inside the outer container 10. It may be formed by

The outer container 10 and the inner container 20 are made of polyolefin resin, ethylene-vinyl copolymer, styrene resin, vinyl resin, polyamide resin, polyester resin, polycarbonate resin, polyphenylene oxide resin, or raw material. Molded using degradable resin. Preferably, the outer container 10 and the inner container 20 are molded using polyolefin resin or polyester resin. More preferably, the outer container 10 and the inner container 20 are molded using polyester resin. Examples of the polyester resin include resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and copolyesters thereof. Particularly preferably, the outer container 10 and the inner container 20 are molded using polyethylene terephthalate resin.

The outer container 10 and the inner container 20 have residual strain because the heated preforms 100 and 200 are stretched in a blow mold and then cooled and molded. Therefore, when the multiple container 1 is heated after molding, the residual strain existing in the outer container 10 and the inner container 20 is relaxed, and thermal contraction occurs. In particular, in the multi-layered container 1, heat shrinkage occurs due to heating when the container is subjected to heat sterilization treatment or hot filling in the filling process performed after molding.

When heat shrinkage occurs after molding, the content of the multiple container 1 is lower due to the fact that the stretching ratio is larger than that of the outer container 10 and that the effect of relaxing the residual strain due to heat setting is smaller than that of the outer container 10. The amount of heat shrinkage of the container 20 tends to be larger than that of the outer container 10. Therefore, in the multiple container 1, the outer surface of the inner container 20, which was in close contact with the inner surface of the outer container 10, peels off from the inner surface of the outer container 10 due to heat shrinkage after molding, and the gap between the outer container 10 and the inner container 20 is removed. A void A may be formed in the space. The gap A is a space formed between the outer container 10 and the inner container 20 when the outer container 10 and the inner container 20 are separated.

In the multi-layered container 1, if the radial length of the void A is sufficiently large, the void A can sufficiently exhibit a heat insulating effect and maintain the temperature of the contents, thereby making it possible to maintain the deliciousness of the contents. I can do it. However, in normal multi-layered containers, when the outer container and the inner container are molded using the same type of resin, the adhesion between the outer container and the inner container is large due to their compatibility. is difficult to peel off, and large voids A are difficult to form. On the other hand, if the outer container and the inner container are molded using different types of resin, the molding process may become complicated and the cost of the resin material may increase.

Therefore, the multiple container 1 is molded using the same type of resin, has heat resistance applicable to hot filling, and has a large void A that can sufficiently exhibit a heat insulation effect, which is formed by heat shrinkage after molding. configured to be Specifically, the multiple container 1 includes a peeling part 30 between the outer container 10 and the inner container 20 for peeling off the inner surface of the outer container 10 and the outer surface of the inner container 20.

The peeling part 30 is provided on at least one of the inner surface of the outer container 10 and the outer surface of the inner container 20. Preferably, the peeling section 30 is formed at least between the shoulder 4 of the outer container 10 and the shoulder 4 of the inner container 20 and between the body 5 of the outer container 10 and the body 5 of the inner container 20. provided in one. That is, the peeling part 30 does not need to be provided between the bottom 6 of the outer container 10 and the bottom 6 of the inner container 20.

When the peeling part 30 is provided between the bottom part 6 of the outer container 10 and the bottom part 6 of the inner container 20, in the multiple container 1, the bottom part 6 of the inner container 20 is removed from the outer container 10 due to heat shrinkage after molding. There is a possibility that it will peel off from the bottom part 6 and float up. In this case, in the multiple container 1, the inner container 20 may contract irregularly, and a uniform gap A may not be formed in the shoulder portion 4 and the body portion 5. In addition, in this case, in the multi-layered container 1, the center of gravity of the entire container filled with contents moves upward, making it more likely to fall over, or the volume of the storage space S becomes smaller, reducing the amount of contents filled. There is a possibility that Therefore, the peeling part 30 is formed between the shoulder 4 of the outer container 10 and the shoulder 4 of the inner container 20 and at least one part between the body 5 of the outer container 10 and the body 5 of the inner container 20. It will be established in

The peeling section 30 is composed of a peeling agent 31 that is solid at room temperature. The material used for the release agent 31 may be at least one of wax and solid oil. Examples of solid fats and oils used in the release agent 31 include palm oil, coconut oil, cocoa butter, and shea butter. The wax used in the release agent 31 may be a plant-derived wax, an animal-derived wax, a petroleum-derived wax, a mineral-derived wax, or a synthetic wax.

Examples of plant-derived waxes include carnauba wax, wood wax, rice wax, and candelilla wax. Examples of animal-derived waxes include beeswax and wool wax. Examples of petroleum-derived waxes include paraffin wax and microcrystalline wax. Examples of mineral-derived waxes include montan wax and the like. Examples of synthetic waxes include hydrocarbon waxes such as FT (Fischer Tropsch) waxes, polyethylene waxes, and the like.

Among such solid fats and waxes, a material suitable for the release agent 31 is paraffin wax. More preferably, the material used for the release agent 31 is paraffin wax containing normal paraffin as a main component.

The melting point of the release agent 31 is 30°C or more and 100°C or less, preferably 30°C or more and 70°C or less. The peeling unit 30 heats and melts the release agent 31, which is solid at room temperature, and applies the molten release agent 31 to at least one of the inner surface of the stretched portion N of the preform 100 and the outer surface of the stretched portion N of the preform 200. It is formed by applying it to one. FIG. 2 shows a release agent 31 applied to portions of the outer surface of the stretched portion N of the preform 200 that correspond to the shoulder portion 4 and the body portion 5. As shown in FIG. The method of applying the molten release agent 31 may be spraying, application with a brush, dipping, or the like. Although it is possible to provide the release agent 31 on at least one surface of the preforms 100 and 200 by bleeding, it is difficult to provide the release agent 31 at a desired position and with a desired thickness.

When the melting point of the release agent 31 is 30° C. or higher, the release agent 31 becomes solid at room temperature. Therefore, when the molten release agent 31 is applied to at least one of the preforms 100 and 200, it is immediately cooled and solidified. Thereby, the molten release agent 31 is applied to a desired position and at a desired thickness without causing dripping. Therefore, in the multiple container 1, the peeling portion 30 can be stably formed at a desired position and with a desired thickness, compared to the case where a liquid peeling agent at room temperature such as heat-resistant silicone oil or liquid paraffin is used. Furthermore, the preforms 100 and 200 can be easily handled even after the release agent 31 has been applied. In particular, after the release agent 31 is applied to the preforms 100 and 200, they can be stored and transported in a stacked state. As a result, in the multiple container 1, the preforms 100 and 200 do not need to be blow-molded immediately after the release agent 31 is applied, so that the degree of freedom in designing the manufacturing process can be increased.

When the melting point of the release agent 31 is 70° C. or lower, it can be melted with relatively simple heating equipment, and the viscosity of the melted release agent 31 becomes relatively low. Therefore, in the multiplex container 1, the work of heating the release agent 31, which is solid at room temperature, and the work of applying the molten release agent 31 can be easily performed, and the molten release agent 31 can easily wet the preforms 100 and 200. Become. Further, when the melting point of the release agent 31 is 70° C. or lower, the release agent 31 tends to be in a molten state when the outer container 10 and the inner container 20 are thermally shrunk after molding. In particular, when the outer container 10 and the inner container 20 are molded using polyester resin, preferably polyethylene terephthalate resin, the temperature at which thermal contraction of the outer container 10 and the inner container 20 starts is 80° C. or higher and 95° C. or lower. Often. Therefore, in this case, if the melting point of the release agent 31 is 70° C. or lower, the release agent 31 is likely to be in a molten state when the outer container 10 and the inner container 20 are thermally shrunk after being molded. As a result, in the multiple container 1, the outer container 10 and the inner container 20 are likely to separate from each other due to heat shrinkage after molding, and it becomes easier to stably form a gap A large enough to sufficiently exhibit a heat insulating effect.

As described above, the multiple container 1 according to the first embodiment includes the peeling part 30 made of a peeling agent that is solid at room temperature between the outer container 10 and the inner container 20. Therefore, in the multiple container 1 according to the first embodiment, the release agent 31 can be applied without causing dripping, and the release part 30 can be easily formed at a desired position and with a desired thickness. As a result, in the multiple container 1 according to the first embodiment, the outer container 10 and the inner container 20 can be easily separated, so that a large gap A that can sufficiently exhibit the heat insulation effect is stably formed. be able to. Therefore, the multiple container 1 according to the first embodiment can easily and stably realize the heat retention function of the contents, and can maintain the deliciousness of the contents.

Further, in the multiple container 1 according to the first embodiment, the outer container 10 and the inner container 20 are molded using a polyester resin, preferably a polyethylene terephthalate resin. As a result, the multiplex container 1 according to the first embodiment not only has high recycling efficiency, but also suppresses the complexity of the molding process and the increase in the cost of the resin material, while maintaining a sufficient heat insulation effect. It is possible to stably form voids A as large as possible. Therefore, the multiple container 1 according to the first embodiment can not only easily and stably realize the heat retention function of the contents, but also can improve the efficiency of recycling.

Furthermore, in the multiple container 1 according to the first embodiment, the melting point of the release agent 31 is 30°C or more and 70°C or less. Therefore, in the multiple container 1 according to the first embodiment, the release agent 31 can be applied with relatively simple equipment and work, and the release part 30 can be easily formed. The outer container 10 and the inner container 20 are likely to separate. Thereby, in the multiple container 1 according to the first embodiment, it is possible to more stably form the voids A that are large enough to sufficiently exhibit the heat insulating effect. Therefore, the multiple container 1 according to Embodiment 1 can more easily and stably realize the function of keeping the contents warm.

Furthermore, in the multiple container 1 according to the first embodiment, the release agent 31 is paraffin wax. That is, in the multiplex container 1 according to the first embodiment, the peeling portion 30 can be formed using a cold-solid peeling agent that is inexpensive and easily available. As a result, in the multiple container 1 according to the first embodiment, the outer container 10 and the inner container 20 can be easily separated, so that a gap A large enough to sufficiently exhibit the heat insulation effect is stably formed. be able to. Therefore, the multiple container 1 according to Embodiment 1 can more easily and stably realize the function of keeping the contents warm.

Furthermore, in the multiple container 1 according to the first embodiment, the peeling section 30 is located between the shoulder 4 of the outer container 10 and the shoulder 4 of the inner container 20, and between the body 5 of the outer container 10 and the inner container 20. It is provided in at least one portion between the body portion 5 and the body portion 5 . That is, in the multiple container 1 according to the first embodiment, the peeling section 30 is not provided between the bottom 6 of the outer container 10 and the bottom 6 of the inner container 20. As a result, in the multiple container 1 according to Embodiment 1, it is possible to prevent the bottom part 6 of the inner container 20 from rising and the inner container 20 from contracting irregularly. The void A can be stably formed. Therefore, in the multiple container 1 according to the first embodiment, the function of keeping the contents warm can be more easily and stably realized.

[Other embodiments]
The multiple container 1 according to the second embodiment will be explained. In the description of the multiplex container 1 according to the second embodiment, descriptions regarding the same configuration and operation as the multiplex container 1 according to the first embodiment will be omitted because the description will be redundant.

FIG. 3 is a diagram schematically showing a longitudinal section of the multiple container 1 according to the second embodiment. Note that FIG. 3 shows the multiple container 1 after the inner surface of the outer container 10 and the outer surface of the inner container 20 have been separated.

The multiple container 1 according to the second embodiment further includes an outside air introduction hole 11 that can introduce outside air between the outer container 10 and the inner container 20. Specifically, the outside air introduction hole 11 may be provided in the mouth portion 3 of the outer container 10 and communicated with the gap A, as shown in FIG. Alternatively, the outside air introduction hole 11 may be provided as a slit in a portion where the mouth portion 3 of the outer container 10 and the mouth portion 3 of the inner container 20 are fixed.

In the multiple container 1 according to the first embodiment, the outer surface of the inner container 20 that was in close contact with the inner surface of the outer container 10 peels off from the inner surface of the outer container 10, and a gap A is formed between the outer container 10 and the inner container 20. Then, the gap A can be in a near-vacuum state. Since it is difficult for heat to transfer in the void A in a state close to a vacuum, the multiple container 1 according to the first embodiment can exhibit a high heat insulation effect.

On the other hand, in the multiple container 1 according to the second embodiment, when the outer surface of the inner container 20 that has been in close contact with the inner surface of the outer container 10 is peeled off from the inner surface of the outer container 10, the outside air flows from the outside air introduction hole 11 toward the gap A. be introduced. As a result, in the multiple container 1 according to the second embodiment, the inner container 20 is easily peeled off from the outer container 10, so that the gap A can be formed more easily than in the first embodiment.

Further, in the multiplex container 1 according to the second embodiment, since outside air is introduced into the gap A from the outside air introduction hole 11, the pressure in the gap A becomes equivalent to atmospheric pressure. As a result, in the multiple container 1 according to the second embodiment, the pressure is the same on the outside and inside of the outer container 10, so deformation of the outer container 10 can be suppressed without increasing the rigidity of the outer container 10. be able to.

[others]
In the embodiment described above, the multiple container 1 is an insulated bottle that maintains the temperature of the contents through the insulation effect of the void A. However, the multiple containers 1 may be freshness-keeping bottles that contain contents such as liquid seasonings or liquid cosmetics and maintain their freshness. The freshness-keeping bottle is also called a delaminated bottle or an airless bottle.

In the multiple container 1 which is a freshness preservation bottle, the basic configurations of the outer container 10, the inner container 20, and their preforms 100 and 200 are the same as in each of the above-described embodiments. However, the multiplex container 1, which is a freshness-preserving bottle, is provided with the outside air introduction hole 11 shown in Embodiment 2, and a cap with a check valve is attached to the opening 3. In the multiplex container 1, which is a freshness-preserving bottle, when the outer container 10 is squeezed, the contents are poured out and the inner container 20 contracts, and outside air is introduced from the outside air introduction hole 11 and the check valve operates. As a result, the contracted state of the inner container 20 is maintained. As a result, in the multiplex container 1, which is a freshness-preserving bottle, the inner container 20 shrinks as the contents decrease, and the inflow of outside air from the spout 21 is suppressed, thereby suppressing the oxidation of the contents. It can maintain its freshness.

Particularly, in the multiplex container 1 which is a freshness preservation bottle, the provision of the peeling part 30 between the outer container 10 and the inner container 20 means that the inner container 20 can be peeled off from the outer container 10 after molding during the peeling process. This is effective because it makes it easier to peel off 20. Furthermore, in the multiple container 1 which is a freshness preservation bottle, providing the peeling part 30 between the outer container 10 and the inner container 20 reduces friction between the outer container 10 and the inner container 20 that occurs during the squeeze operation. However, it is effective because the pronunciation caused by this can be suppressed.

In the above-described embodiment, the multiplex container 1 is a container in which the outer container 10 constitutes the outer shell of the multiplex container 1 and the inner container 20 stores the contents. However, the multiple container 1 is not limited to a container in which the outer container 10 constitutes the outer shell of the multiple container 1 and the inner container 20 stores the contents. That is, in the multiplex container 1, the container forming the outer shell of the multiplex container 1 may be provided further outside the outer container 10, or the container accommodating the contents may be provided further inside the inner container 20. In this way, the multiple container 1 only needs to function as a laminate in which the outer container 10 and the inner container 20 are peelably stacked adjacent to each other and form a gap A between them. The container may have a triple or more multi-layered structure in which a plurality of voids A can be formed.

In the embodiment described above, the multiple containers 1 correspond to an example of the "multiple containers" described in the claims. The outer container 10 corresponds to an example of the "outer container" described in the claims. The inner container 20 corresponds to an example of an "inner container" described in the claims. The peeling part 30 corresponds to an example of a "peeling part" described in the claims. The release agent 31 corresponds to an example of a "release agent" described in the claims. The outside air introduction hole 11 corresponds to an example of the "outside air introduction hole" described in the claims. The shoulder portion 4 corresponds to an example of a “shoulder portion” described in the claims. The trunk 5 corresponds to an example of the "trunk" described in the claims. The preform 100 corresponds to an example of a "preform" corresponding to the "outer container" described in the claims. The preform 200 corresponds to an example of a "preform" corresponding to the "inner container" described in the claims.

The techniques of the embodiments described above can be applied to each other including modifications. The above-described embodiments do not limit the content of the present invention, and changes can be made without departing from the scope of the claims.

The terms used in the embodiments described above and in the claims should be construed as non-limiting terms. For example, the term "comprising" should be interpreted as "including but not limited to what is described as including." The term "comprising" should be interpreted as "not limited to what is described as comprising." The term "comprising" should be interpreted as "not limited to what is described as having."

1 Multiple container 3 Mouth 4 Shoulder 5 Body 6 Bottom 10 Outer container 11 Outside air introduction hole 20 Inner container 21 Outlet 30 Peeling part 31 Release agent 100 Preform 200 Preform A Gap M Non-stretched part N Stretched part S Storage Space Z center axis

Claims (4)

The inner preform corresponding to the inner container that can be filled with contents and the outer preform corresponding to the outer container are formed by stretch blowing, and the inner container and the outer container enclosing the inner container are formed. A bottle-shaped multiple container stacked in a peelable manner,
The outer container and the inner container are molded using polyester resin,
A peeling part made of a peeling agent that is solid at room temperature is provided between the outer container and the inner container,
The melting point of the release agent is 30°C or more and 70°C or less,
The peeling part is
The inner surface of the portion of the outer preform that is stretched by the stretch blow and corresponds to the shoulder and body portions excluding the bottom of the outer container, and the inner surface of the stretched portion of the inner preform that is stretched by the stretch blow. It is provided by applying the molten release agent to at least one of the outer surfaces of the parts corresponding to the shoulders and the body excluding the bottom of the inner container ,
The multiple containers are:
Due to heat shrinkage after molding, the shoulder and body of the inner container are separated from the shoulder and body of the outer container via the peeling portion, thereby creating a gap between the inner container and the outer container. formed, and the void is maintained in a state in which the inner container is filled with the content ;
Multiple containers. The peeling portion includes a mouth portion of the outer container corresponding to a non-stretched portion of the outer preform that is not stretched even by the stretching blow, and a mouth portion of the inner container corresponding to the non-stretched portion of the inner preform. It is not provided between
The mouth of the outer container is provided with an outside air introduction hole that can introduce outside air between the outer container and the inner container.
Multiple containers according to claim 1. The release agent is paraffin wax.
The multiple container according to claim 1 or 2. By stretching and blowing an inner preform corresponding to an inner container that can be filled with contents and an outer preform corresponding to an outer container, the inner container and the outer container containing the inner container can be separated. A method for manufacturing a multiple container, comprising: forming a bottle-shaped multiple container stacked on top of each other,
The outer container and the inner container are molded using polyester resin, and
A peeling part made of a peeling agent that is solid at room temperature is provided between the outer container and the inner container,
The melting point of the release agent is 30°C or more and 70°C or less,
The peeled part is
The inner surface of the portion of the outer preform that is stretched by the stretch blow and corresponds to the shoulder and body portions excluding the bottom of the outer container, and the inner surface of the stretched portion of the inner preform that is stretched by the stretch blow. Provided by applying the molten release agent to at least one of the outer surfaces of the parts corresponding to the shoulders and the body excluding the bottom of the inner container,
The multiple containers are:
Due to heat shrinkage after molding, the shoulder and body of the inner container are separated from the shoulder and body of the outer container via the peeling portion, thereby creating a gap between the inner container and the outer container. formed, and the void is maintained in a state in which the inner container is filled with the content ;
Method for manufacturing multiple containers.