Delamination container and preform

A delamination container includes an engaging protrusion that is provided in an area extending over at least a ground contact portion and a recess and protrudes from either one of an outer layer body and an inner layer body and engages with the other in an undercutting manner. Further, a preform includes an engaging protrusion that is provided in an area extending from at least a boundary between a bottom and a trunk to just before an axial center of the bottom and protrudes from either one of an outer body and an inner body and engages with the other in an undercutting manner.

TECHNICAL FIELD

The present disclosure relates to a synthetic resin delamination container including an outer layer body and an inner layer body laminated on an inner surface of the outer layer body and a resin preform used for blow molding of the delamination container.

BACKGROUND

Conventionally, as a container for holding food seasonings such as soy source and beverages, or cosmetics such as skin lotion and toiletries such as shampoo, rinse and liquid soap as a content liquid, a delamination container also called as a peelable laminated container is known (see, for example, PTL1).

Such a delamination container has a double structure in which a volume-reducible and deformable inner layer body including a space for holding a content liquid is peelably laminated on an inner surface of an outer layer body. The outer layer body has a tubular mouth, a trunk connected to the mouth and a bottom configured to block a lower end of the trunk and forms an outer shell of the container. The container is used as a squeeze type dispensing container combined with a dispensing cap with a check valve or as a container with pump combined with a pump. In this case, a content liquid can be dispensed outside by squeezing the trunk of the outer layer body or by operating the pump. On the other hand, after dispense, the ambient air is introduced between the inner layer body and the outer layer body through an ambient air inlet hole provided in the outer layer body, and the outer layer body can be restored to its original shape while the inner layer body undergoes volume reduction and deformation. As described above, with a delamination container, a content liquid held in the inner layer body can be dispensed without being replaced with the ambient air. Thus contact of the content liquid held in the inner layer body with the ambient air is reduced, and deterioration and change in quality of the content liquid can be suppressed.

The aforementioned delamination container can be produced by forming a tubular parison having a laminate structure and blow molding the parison in a mold. In the laminate structure, an inner body is laminated inside of an outer body by coextrusion molding of an olefin-based synthetic resin material for the outer layer body such as polypropylene (PP) and polyethylene (PE), for example, and a synthetic resin material for an inner layer body such as nylon and ethylene vinyl alcohol copolymer resin (EVOH) having a low compatibility with the synthetic resin material for the outer layer body.

In a dispensing container that uses a delamination container, when the inner layer body separates from the outer layer body and the container undergoes irregular volume reduction and deformation as the content liquid is dispensed therefrom, the inner surfaces of the inner layer body adhere to each other between the mouth and the bottom, which causes a dispensing path of the content liquid to be narrowed or blocked. Thus the dispensing operability may be impaired and the content liquid may not be dispensed to the end.

Therefore, a pair of longitudinal zonal adhesion layers is provided on both sides across an axial center of the container, each of the layers being provided between the outer layer body and the inner layer body to adhere them to each other. Thus deformation of the inner layer body as the content liquid is dispensed is suppressed by these adhesion layers, and the dispensing path can be secured in the inner layer body until the content liquid is used up. Further, a technique is known by which either one of the inner body and the outer body is used as an insert material to injection mold a bottomed tubular preform, and the preform is molded into a delamination container by biaxial stretching blow molding (see, for example, PTL 2). In this case, the inner layer body and the outer layer body of the molded container are assembled at and fixed to a predetermined portion of the trunk in an undercutting manner. CITATION LIST

Patent Literature

SUMMARY

Technical Problem

However, when a preform formed into a laminate structure having an outer body and an inner body is produced by using the insert molding (injection molding), even if an outer layer body and an inner layer body of a container molded from the preform are fixed to a predetermined part of a trunk, a volume reduction state of the inner layer body becomes unstable on the bottom. Thus, when a pump is attached, for example, a flow path of a pipe for pumping is blocked, and dispensing operability may be impaired or the content liquid cannot be dispensed to the end. Thus there is room for improvement of the above problems.

The present disclosure has been conceived in view of the above problems, and the present disclosure is to provide a delamination container that can prevent inner surfaces of an inner layer body from being adhered to each other during use, and a preform used for blow molding of the delamination container.

Solution to Problem

The disclosed delamination container is a synthetic resin delamination container including an outer layer body and an inner layer body peelably laminated on an inner surface of the outer layer body. The container has a tubular mouth, a trunk connected to the mouth, a bottom configured to include a ground contact portion and a recess provided on an axial center side of the ground contact portion and to block a lower end of the trunk, and an engaging protrusion configured to be provided in an area of the bottom, the area extending over at least the ground contact portion and the recess, and to protrude from either one of the outer layer body and the inner layer body and engage with the other one of the outer layer body and the inner layer body in an undercutting manner.

In the disclosed delamination container configured in the aforementioned manner, preferably, the engaging protrusion is provided at least in a pair of areas of the bottom, the areas being opposed to each other across an axial center of the bottom and extending over the ground contact portion and the recess.

In the disclosed delamination container configured in the aforementioned manner, preferably, a cross section vertical to an extending direction of the engaging protrusion is T-shaped.

In the disclosed delamination container configured in the aforementioned manner, preferably, the engaging protrusion is integral with the inner layer body and protrudes from the inner layer body toward the outer layer body.

In the disclosed delamination container configured in the aforementioned manner, preferably, the engaging protrusion extends along the axial center of the mouth and the trunk from the bottom through the trunk to the mouth.

The disclosed preform is a synthetic resin preform used for blow molding, the preform including an outer body and an inner body laminated on an inner surface of the outer body. The preform has a tubular mouth, a trunk connected to the mouth, a bottom configured to block a lower end of the trunk, and an engaging protrusion configured to be provided in an area of the bottom, the area extending at least from a boundary between the bottom and the trunk to just before an axial center of the bottom, and to protrude from either one of the outer body and the inner body and engage with the other one of the outer body and the inner body in an undercutting manner.

In the disclosed preform configured in the aforementioned manner, preferably, the engaging protrusion is provided at least in a pair of areas of the bottom, the areas being opposed to each other across the axial center of the bottom and extending from the boundary between the bottom and the trunk to just before the axial center of the bottom.

In the disclosed preform configured in the aforementioned manner, preferably, a cross section vertical to an extending direction of the engaging protrusion is T-shaped.

In the disclosed preform configured in the aforementioned manner, preferably, the engaging protrusion is integral with the inner body and protrudes from the inner body toward the outer body.

In the disclosed preform configured in the aforementioned manner, preferably, the engaging protrusion extends along the axial center of the mouth and the trunk from the bottom through the trunk to the mouth.

Advantageous Effect

According to the present disclosure, a delamination container that can prevent inner surfaces of an inner layer body from being adhered to teach other during use and a preform used for blow molding of the delamination container can be provided.

DETAILED DESCRIPTION

The present disclosure will be described in more detail below with reference to the drawings.

The delamination container1according to an embodiment of the present disclosure illustrated inFIG. 1is also called as a peelable laminated container. The container has a double structure in which an outer layer body2and an inner layer body3are included, and an external shape thereof is a bottle shape having a cylindrical mouth4, a cylindrical trunk5connected below the mouth4and a bottom6configured to block a lower end of the trunk5.

The mouth4is provided with a male screw4ato allow for screwing a dispensing member such as a dispensing cap and a dispensing pump therewith to fix to the mouth4. Further, the bottom6includes a ground contact portion6aconfigured to annularly protrude downward and a recess6bprovided on the axial center O1side of the ground contact portion6aof the bottom6. The delamination container1can be disposed in a standing manner by bringing the ground contact portion6ain contact with the ground.

It is to be noted that the mouth4may include, instead of the male screw4a, an annular protrusion such that a dispensing member such as a dispensing cap is plugged to be engaged therewith in an undercutting manner.

The case where the delamination container1is used as a squeeze type dispensing container is taken as an example and illustrated below.

The outer layer body2forms an outer shell of the delamination container1, and can be formed, for example, by a synthetic resin material such as polypropylene (PP), polyethylene (PE) and polyethylene terephthalate (PET). The portion corresponding to the trunk5of the outer layer body2is flexible, and can dent when squeezed and restore from the dented state to the original shape. When the delamination container1is used as a container with pump, the portion corresponding to the trunk5of the outer layer body2is not necessarily formed to be squeezable.

The inner layer body3is formed into a bag-like shape that is thinner than the outer layer body2by using the synthetic resin material of nylon and ethylene vinyl alcohol copolymer resin (EVOH) which has a low compatibility with the synthetic resin material that forms the outer layer body2. The inner layer body3is peelably laminated on the inner surface of the outer layer body2. The inside of the inner layer body3is a holding portion7connected to an opening of the mouth4, and food seasonings such as soy source, beverages, cosmetics such as skin lotion and toiletries such as shampoo, rinse and liquid soap can be held, as a content liquid, in the holding portion7. It is to be noted that an annular flange configured to radially and outwardly protrude is provided at the opening portion of the inner layer body3, and the opening portion of the inner layer body3is fixed to the open end when the flange is bridged over (mounted on) the open end of the outer layer body2.

Although not illustrated in detail, the outer layer body2is provided with an ambient air inlet hole configured to introduce the ambient air between the outer layer body2and the inner layer body3. Although the ambient air inlet hole can be provided in a position corresponding to the mouth4of the outer layer body2, for example, it can be provided also in the position corresponding to the trunk5or in the position corresponding to the bottom6. In either cases, preferably, the ambient air inlet hole is configured to have a function as a check valve, or it may be configured, with a check valve mounted, to introduce the ambient air between the outer layer body2and the inner layer body3, but not to flow the air out from between the outer layer body2and the inner layer body3. Further, the ambient air inlet hole can be configured to have neither a check valve nor a check valve function.

The delamination container1configured in the aforementioned manner can be configured as a dispensing container by attaching a dispensing member such as a dispensing cap to the mouth4thereof. In this case, a content liquid can be dispensed from the dispensing member to outside by squeezing a portion corresponding to the trunk5of the outer layer body2, and the inner layer body3separates from the inner surface of the outer layer body2as the content liquid is dispensed, thus can undergo volume reduction and deformation. When the squeezing is discontinued, the ambient air is introduced from the ambient air inlet hole provided in the outer layer body2to between the outer layer body2and the inner layer body3, and thus the outer layer body2can be restored to its original shape while the inner layer body3undergoes volume reduction and deformation. Therefore, the content liquid held in the holding portion7can be dispensed without being displaced with the ambient air. Thus contact of the content liquid held in the holding portion7with the ambient air is reduced, and deterioration and change in quality of the content liquid can be prevented.

In the disclosed delamination container1, in order to prevent the inner layer body3from being irregularly volume reduced and deformed as the content liquid is dispensed, an engaging protrusion10is provided in an area A1extending over at least the ground contact portion6aand the recess6bof the bottom6. In the present embodiment, in order to achieve more stable volume reduction and deformation of the inner layer body3, each of a pair of areas A1is provided with the engaging protrusion10, the areas being opposed to each other across at least the axial center O1of the bottom6and extending over the ground contact portion6aand the recess6bthereof. The area A1does not reach the axial center O1of the bottom6, and near the axial center O1of the bottom6is not provided with the engaging protrusion10. In other words, a pair of engaging protrusions10is provided only on both sides across the axial center O1of the bottom6.

It is to be noted that, in the present embodiment, although the engaging protrusion10is not provided near the axial center O1of the bottom6, it is not limited thereto, and if the engaging protrusion10is provided at least in the area A1, the engaging protrusion10may be extended to the axial center O1of the bottom6such that the engaging protrusion10is provided up to the part of the axial center O1.

These engaging protrusions10are provided to either one of the outer layer body2and the inner layer body3in a pair of areas A1. In the present embodiment, a case where a pair of engaging protrusions10is integrally provided with the inner layer body3is illustrated.

Each of the pair of engaging protrusions10extends zonally along a virtual plane that includes the axial center O1common to the mouth4, the trunk5and the bottom6, and a cross section (transverse section) thereof vertical to the extending direction is T-shaped as illustrated inFIG. 2. Further, each of the pair of engaging protrusions10protrudes from the inner layer body3toward the outer layer body2and engages with the outer layer body2in an undercutting manner. By providing such an engaging protrusion10, the inner layer body3is fixed to the outer layer body2in the area A1of the bottom6so that it is not separated from the outer layer body2. It is to be noted that, in the present embodiment, although the cross-sectional shape of the engaging protrusion10is uniform along the extending direction thereof, the cross-sectional shape may be changed along the extending direction.

Therefore, as illustrated inFIG. 3, even if the inner layer body3undergoes volume reduction and deformation as the content liquid is dispensed, the inner layer body3is fixed to the outer layer body2by the engaging protrusion10in the area A1on both sides across the axial center O1of the bottom6. Thus the inner layer body3stably undergoes volume reduction and deformation, and irregular volume reduction and deformation thereof can be prevented. In this manner, without providing a longitudinal zonal adhesion layer between the outer layer body2and the inner layer body3to adhere them to each other, a pair of engaging protrusions10is provided to prevent the dispensing path of the content liquid from being narrowed or blocked due to adhesion of the inner surfaces of the inner layer body3between the mouth4and the bottom6caused by irregular volume reduction and deformation of the inner layer body3as the liquid content is dispensed. Thus, the dispensing operability of the delamination container1can be maintained and the content liquid held in the holding portion7can be dispensed to the end.

Further, a cross section vertical to the extending direction of the pair of engaging protrusions10is formed into T-shape. Thus, with a simple structure, the inner layer body3can reliably be engaged with the outer layer body2in an undercutting manner. Moreover, the inner layer body3which is formed thinner than the outer layer body2is provided with the pair of engaging protrusions10. Thus the pair of engaging protrusions10can be reliably engaged with the outer layer body2, which is thicker, in an undercutting manner. Therefore, the pair of engaging protrusions10allows the inner layer body3to be fitted to the outer layer body2in more robust manner.

As illustrated inFIG. 1, in the present embodiment, each of the pair of engaging protrusions10is provided not only in the area A1of the bottom6, but also along the axial center O1common to the trunk5and the bottom6extending from the bottom6through the trunk5to the mouth4. In other words, the pair of engaging protrusions10is provided not only in the area A1of the bottom6, but also on both sides across the axial center O1of the trunk5and the mouth4.

In this manner, the pair of engaging protrusions10is provided not only in the area A1of the bottom6but also on both sides across the axial center O1of the trunk5and the mouth4, and as a result, as illustrated inFIG. 3, the inner layer body3is fixed to the outer layer body2not only in the areas A1on both end sides across the axial center O1of the bottom6but also on both sides of the trunk5and the mouth4. Thus the irregular volume reduction and deformation of the inner layer body3as the content liquid is dispensed can be suppressed in all areas over the mouth4, the trunk5and the bottom6. In this manner, narrowing and blocking of the dispensing path of the content liquid caused by adhesion between the inner surfaces of the inner layer body3between the mouth4and the bottom6can be prevented in more reliable manner.

The delamination container1can be formed by blow molding the synthetic resin preform11illustrated inFIG. 4, which is an embodiment of the present disclosure.

The preform11has a double structure in which a synthetic resin outer body12forming the outer layer body2and a synthetic resin inner body13forming the inner layer body3are included, and the exterior shape thereof is a bottomed tubular shape (substantially test tube shape) having a cylindrical mouth14, a cylindrical trunk15connected below the mouth14and a bottom16configured to block a lower end of the trunk15. It is to be noted that the mouth14is formed into a shape corresponding to the mouth4of the delamination container1, and the bottom16is formed into a curved shape (hemisphere shape).

The outer body12is formed by the same synthetic resin materials as those used for the outer layer body2, that is, synthetic resin materials such as polypropylene (PP), polyethylene (PE) and polyethylene terephthalate (PET). The inner body13is also formed by the same synthetic resin materials as those used for the inner layer body3, that is, synthetic resin materials such as nylon and ethylene vinyl alcohol copolymer resin (EVOH) which has a low compatibility with the synthetic resin material that forms the outer body12. The inner body13is formed thinner than the outer body12and is laminated on the inner surface of the outer body12such that it covers all over the inner surface.

Corresponding to the pair of engaging protrusions10of the delamination container1, the disclosed preform11is provided with engaging protrusions20respectively provided in a pair of areas A2. The pair of areas A2is opposed to each other across at least the axial center O2of the bottom16and extends from the boundary between the bottom16and the trunk15to just before the axial center O2of the bottom16.

Although the preform11is formed by injection molding in which an injection molding mold is used, a gate of the injection molding mold is provided at the axial center O2of the bottom16of the preform11. Thus, the area A2is provided avoiding the axial center O2of the bottom16, and the engaging protrusion20is not provided near the axial center O2of the bottom16. In this manner, the pair of engaging protrusions20is provided only on both end sides across the axial center O2of the bottom16.

It is to be noted that, in the present embodiment, the engaging protrusion20is not provided near the axial center O2of the bottom16to avoid the gate of the injection molding mold. However, it is not limited thereto, and as long as the engaging protrusion20is provided at least in the areas Az, when the gate of the injection molding mold is provided at other positions such as the mouth14and the trunk15, for example, the engaging protrusion20may be extended to the axial center O2of the bottom16such that the engaging protrusion20is provided up to the part of the axial center Oz. Further, the engaging protrusion20may also be provided up to the axial center O2of the bottom16, which will serve as a gate of the injection molding mold.

These engaging protrusions20are provided to either one of the outer body12and the inner body13in a pair of areas A2. In the present embodiment, a case where a pair of engaging protrusions20is integrally provided with the inner body13is illustrated.

Each of the pair of engaging protrusions20extends zonally along a virtual plane that includes the axial center O2common to the mouth14, the trunk15and the bottom16, and as illustrated inFIG. 4A, a cross section vertical to the extending direction thereof is T-shaped. Further, each of the pair of engaging protrusions20protrudes from the inner body13toward the outer body12and engages with the outer body12in an undercutting manner. It is to be noted that the cross-sectional shape of the engaging protrusion20is uniform along the extending direction thereof.

As illustrated inFIG. 4B, in the present embodiment, each of the pair of engaging protrusions20is provided not only in the area A2of the bottom16, but also extending along the axial center O2common to the trunk15and the bottom16from the bottom16through the trunk15to the mouth14. In other words, the pair of engaging protrusions20is provided not only in the area A2of the bottom16but also on both sides across the axial center O2of the trunk15and the mouth14.

The preform11configured in the aforementioned manner can be formed by insert molding in which the inner body13illustrated inFIG. 5is used as an insert material. In other words, the inner body13formed in advance in a predetermined shape provided with a pair of engaging protrusions20by injection molding or the like is disposed in a predetermined position of the injection molding mold, and in this state, a synthetic resin material for molding the outer body12is injected into the injection molding mold. In this manner, the preform11can be formed in which the inner body13is laminated on the inner surface of the outer body12such that the outer body12is engaged with the pair of engaging protrusions20in an undercutting manner. In this manner, the preform11in which the pair of engaging protrusions20is engaged with the outer body12in an undercutting manner can be easily produced by insert molding in which the inner body13provided with the pair of engaging protrusions20is used as an insert material. In this case, injection molding of the inner body13to be used as an insert material and insert molding of the preform11in which the inner body13is used as an insert material may be performed in one mold. Alternately, after injection molding of the inner body13to be used as an insert material, the inner body13may be transferred to another mold for insert molding and therein the preform11may be insert molded.

The delamination container1illustrated inFIG. 1can be produced by blow molding the aforementioned perform 11.

In other words, as illustrated inFIG. 6, the preform11is set in a mold for blow molding30that constitutes the blow molding apparatus such that the mouth14projects from the cavity30aand the trunk15and the bottom16are positioned in the cavity30a, and in this state, pressurizing medium such as pressurized air and pressurized liquid for blow molding is supplied from a supply device not illustrated through its mouth14into the preform11. In this manner, as illustrated inFIG. 7, the preform11is blow molded into a shape conforming to an inner surface of the cavity30aand can be formed into the delamination container1. In this case, biaxial stretching blow molding by which a pressurizing medium is supplied while the preform11is longitudinally stretched by using a stretching rod can be adopted.

It goes without saying that the present disclosure is not limited to the aforementioned embodiment, and various changes may be made without departing from the gist of the present disclosure.

For example, in the delamination container1according to the aforementioned embodiment, although a pair of engaging protrusions10is provided to the inner layer body3, a pair of engaging protrusions10may be provided to the outer layer body2. In the same manner, in the preform11according to the aforementioned embodiment, although a pair of engaging protrusions20is provided to the inner body13, a pair of engaging protrusions20may be provided to the outer body12.

Further, in the delamination container1according to the aforementioned embodiment, although a pair of engaging protrusions10is provided, only one engaging protrusion10or three or more engaging protrusions10may be provided. In the same manner, in the preform11according to the aforementioned embodiment, although a pair of engaging protrusions20is provided, only one engaging protrusion20or three or more engaging protrusions20may be provided.

Moreover, in the delamination container1according to the aforementioned embodiment, although the engaging protrusion10is configured to extend from the bottom6through the trunk5to the mouth4, it is not limited thereto, and as long as the engaging protrusion10is provided in the area A1of the bottom6, it may be configured to extend to the trunk5but not reach the mouth4, or it may be configured to extend to the middle of the trunk5. Thus the area in which the engaging protrusion10is disposed can be changed in various manners. In the same manner, in the preform11according to the aforementioned embodiment, although the engaging protrusion20is configured to extend from the bottom16through the trunk15to the mouth14, it is not limited thereto, and as long as the engaging protrusion20is provided in the area A2of the bottom16, it may be configured to extend to the trunk15but not reach the mouth14, or it may be configured to extend to the middle of the trunk15. Thus the area in which the engaging protrusion20is disposed can be changed in various manners.

Moreover, in the delamination container1according to the aforementioned embodiment, although the mouth4and the trunk5can be formed into a cylindrical shape, it is not limited thereto, and it may be formed into a square tubular shape or an elliptic cylindrical shape, for example. In the same manner, in the preform11according to the aforementioned embodiment, although the mouth14and the trunk15can be formed into a cylindrical shape, it is not limited thereto, and it may be formed into a square tubular shape or an elliptic cylindrical shape, for example.

REFERENCE SIGNS LIST