JP2020157776A - Blow molding method and composite preform - Google Patents

Abstract

To provide a blow molding method and a composite preform capable of imparting various functions and characteristics to a container.SOLUTION: First, a preform 10a made of a plastic material is prepared and an outer contraction member 40 is provided outside the preform 10a. The preform 10a and the outer contraction member 40 are then heated to produce a composite preform 70 having the preform 10a and the outer contraction member 40 closely adhered to the outside of the preform. Following that, the composite preform 70 is heated and inserted into a blow molding mold 50, and blow molding is applied to the composite preform 70 inside the blow molding mold 50 to integrally expand the preform 10a and the outer contraction member 40 of the composite preform 70 so as to obtain a composite container 10A.SELECTED DRAWING: Figure 4

Description

The present invention mainly relates to a blow molding method and a composite preform for molding a composite container for containing a content liquid such as food and drink.

Recently, plastic bottles have become common as bottles for containing the contents of foods and drinks, and such plastic bottles contain the contents.

A plastic bottle containing such a content liquid is manufactured by inserting a preform into a mold and biaxially stretching blow molding.

By the way, in the conventional biaxial stretching blow molding method, a container shape is formed by using a preform containing, for example, a single layer material such as PET or PP, a multilayer material or a blend material. However, in the conventional biaxial stretching blow molding method, it is general that the preform is simply molded into a container shape. Therefore, when the container is to have various functions and properties (barrier property, heat retention property, etc.), the means thereof is limited, for example, changing the material constituting the preform. In particular, it is difficult to give different functions and characteristics depending on the part of the container (for example, the body and the bottom).

Japanese Unexamined Patent Publication No. 2009-241526

The present invention has been made in view of these points, and an object of the present invention is to provide a blow molding method and a composite preform capable of imparting various functions and characteristics to a container.

In the blow molding method for molding a composite container, the present invention includes a step of preparing a preform made of a plastic material, a step of providing an outer shrink member on the outside of the preform, and heating the preform and the outer shrink member. Thereby, a step of producing a composite preform having the preform and an outer shrinking member adhered to the outside of the preform, a step of heating the composite preform and inserting it into a blow molding die, and a blow molding. This blow molding method is characterized by comprising a step of integrally expanding the preform of the composite preform and the outer shrinking member by performing blow molding on the composite preform in a mold.

The present invention is a blow molding method characterized in that the preform has a mouth portion, a body portion and a bottom portion, and the outer shrinking member is provided so as to cover the body portion and the bottom portion of the preform.

The present invention is characterized in that the preform has a mouth portion, a body portion, and a bottom portion, and the outer shrinking member is provided so as to cover a part of the body portion and the bottom portion of the preform. The method.

The present invention is a blow molding method characterized in that the outer shrinking member has a gas barrier property or a light ray barrier property.

The present invention is a blow molding method characterized in that the outer shrinking member is pre-designed or printed.

The present invention is a blow molding method characterized in that the outer shrinking member is made of a material having higher heat retention or cold retention than the plastic material constituting the preform.

The present invention is a blow molding method characterized in that the outer shrink member is made of a material that is less slippery than the plastic material constituting the preform.

The present invention is characterized in that the composite preform includes a preform made of a plastic material and an outer shrinking member provided on the outside of the preform, and the outer shrinking member is in close contact with the outside of the preform. It is a composite preform to be used.

The present invention is a composite preform characterized in that the preform has a mouth portion, a body portion and a bottom portion, and the outer shrinking member is provided so as to cover the body portion and the bottom portion of the preform.

The present invention is characterized in that the preform has a mouth portion, a body portion, and a bottom portion, and the outer shrinking member is provided so as to cover a part of the body portion and the bottom portion of the preform. It is a reform.

The present invention is a composite preform characterized in that the outer shrinking member has a gas barrier property or a light ray barrier property.

The present invention is a composite preform characterized in that the outer shrinking member is pre-designed or printed.

The present invention is a composite preform characterized in that the outer shrinking member is made of a material having higher heat retention or cold retention than the plastic material constituting the preform.

The present invention is a composite preform characterized in that the outer shrinking member is made of a material that is less slippery than the plastic material constituting the preform.

According to the present invention, the preform of the composite preform and the outer shrinking member are integrally expanded by performing blow molding on the composite preform in the blow molding mold.
Therefore, the preform (container body) and the outer shrinking member can be composed of separate members, and various functions and characteristics can be imparted to the composite container by appropriately selecting the type and shape of the outer shrinking member. it can.

FIG. 1 is a partial vertical sectional view showing a composite container. FIG. 2 is a horizontal sectional view showing a composite container (a sectional view taken along line II-II of FIG. 1). FIG. 3 is a vertical sectional view showing a composite preform according to an embodiment of the present invention. 4 (a) to 4 (g) are schematic views showing a blow molding method according to an embodiment of the present invention. FIG. 5 is a partial vertical sectional view showing a modified example of the composite container. FIG. 6 is a vertical sectional view showing a modified example of the composite preform. 7 (a) to 7 (g) are schematic views showing a modified example of the blow molding method.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 4 are diagrams showing an embodiment of the present invention.

First, the outline of the composite container produced by the blow molding method according to the present embodiment will be described with reference to FIGS. 1 and 2. In addition, in this specification, "upper" and "lower" mean the upper part and the lower part in the state (FIG. 1) in which the composite container 10A is upright, respectively.

As will be described later, the composite container 10A shown in FIGS. 1 and 2 is biaxially stretched with respect to the composite preform 70 (see FIG. 3) including the preform 10a and the outer shrinking member 40 using a blow molding die 50. It is obtained by integrally expanding the preform 10a of the composite preform 70 and the outer shrinking member 40 by performing blow molding.

Such a composite container 10A includes a container body 10 made of a plastic material located inside and an outer shrinking member 40 provided in close contact with the outside of the container body 10.

Of these, the container body 10 includes a mouth portion 11, a neck portion 13 provided below the mouth portion 11, a shoulder portion 12 provided below the neck portion 13, a body portion 20 provided below the shoulder portion 12, and a body. A bottom portion 30 provided below the portion 20 is provided.

On the other hand, the outer shrinking member 40 is in close contact with the outer surface of the container body 10 and is attached to the container body 10 in a state where it does not easily move or rotate.

Next, the container body 10 will be described in detail. As described above, the container body 10 has a mouth portion 11, a neck portion 13, a shoulder portion 12, a body portion 20, and a bottom portion 30.

Of these, the mouth portion 11 has a screw portion 14 screwed to a cap (not shown) and a flange portion 17 provided below the screw portion 14. The shape of the mouth portion 11 may be a conventionally known shape.

The neck portion 13 is located between the flange portion 17 and the shoulder portion 12, and has a substantially cylindrical shape having a substantially uniform diameter. Further, the shoulder portion 12 is located between the neck portion 13 and the body portion 20, and has a shape in which the diameter gradually increases from the neck portion 13 side to the body portion 20 side.

Further, the body portion 20 has a cylindrical shape having a substantially uniform diameter as a whole. However, the present invention is not limited to this, and the body portion 20 may have a polygonal tubular shape such as a quadrangular tubular shape or an octagonal tubular shape. Alternatively, the body portion 20 may have a tubular shape having a non-uniform horizontal cross section from the upper side to the lower side. Further, in the present embodiment, the body portion 20 is not formed with irregularities and has a substantially flat surface, but the present invention is not limited to this. For example, the body portion 20 may have irregularities such as panels or grooves.

On the other hand, the bottom portion 30 has a recess 31 located at the center and a ground contact portion 32 provided around the recess 31. The shape of the bottom portion 30 is not particularly limited, and may have a conventionally known bottom shape (for example, a petaloid bottom shape, a round bottom shape, or the like).

The thickness of the container body 10 in the body portion 20 is not limited to this, but can be reduced to, for example, about 50 μm to 250 μm. Further, the weight of the container body 10 is not limited to this, but can be 10 g to 20 g.

Such a container body 10 can be manufactured by biaxially stretching blow molding a preform 10a (described later) manufactured by injection molding a synthetic resin material. It is preferable to use a thermoplastic resin, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), and PEN (polyethylene naphthalate) as the material of the preform 10a, that is, the container body 10.

Further, the container body 10 can be formed as a multi-layer molded bottle having two or more layers. That is, by extrusion molding or injection molding, for example, the intermediate layer is provided with gas barrier properties such as MXD6, MXD6 + fatty acid salt, PGA (polyglycolic acid), EVOH (ethylene vinyl alcohol copolymer) or PEN (polyethylene naphthalate) and light-shielding properties. As the resin (intermediate layer) to have, a preform 10a composed of three or more layers may be extruded and then blow-molded to form a multi-layer bottle having gas barrier properties and light-shielding properties.

Such a container body 10 may consist of, for example, a bottle having a full filling capacity of 150 ml to 1500 ml.

Next, the outer shrinking member 40 will be described. The outer shrinking member 40 is provided on the outside of the preform 10a as described later, is heated integrally with the preform 10a and adheres to the outside of the preform 10a, and then biaxially stretched and blow-molded together with the preform 10a. It was obtained by doing so.

The outer shrinking member 40 is attached to the outer surface of the container body 10 without being adhered, and is in close contact with the container body 10 so as not to move or rotate. As shown in FIG. 2, the outer shrinking member 40 is provided over the entire circumferential direction so as to surround the container body 10, and has a substantially circular horizontal cross section.

In this case, the outer shrinking member 40 is provided so as to cover the shoulder portion 12, the body portion 20, and the bottom portion 30 of the container body 10, excluding the mouth portion 11 and the neck portion 13. As a result, desired functions and characteristics can be imparted to the shoulder portion 12, the body portion 20, and the bottom portion 30 of the container body 10.

The outer shrinking member 40 may be provided in the entire area or a part of the container body 10 other than the mouth portion 11. For example, the outer shrinking member 40 may be provided so as to cover the entire neck portion 13, shoulder portion 12, body portion 20, and bottom portion 30 of the container body 10 except for the mouth portion 11. Further, the number of outer shrinkage members 40 is not limited to one, and a plurality of outer shrinkage members 40 may be provided. For example, two outer contracting members 40 may be provided on the outer surface of the shoulder portion 12 and the outer surface of the bottom portion 30, respectively.

The outer shrinking member 40 may have an action of shrinking with respect to the preform 10a. It is preferable that the outer shrinking member 40 shrinks (for example, heat shrinks) with respect to the preform 10a when an external action (for example, heat) is applied.

The thickness of the outer shrinking member 40 is not limited to this, but can be, for example, about 50 μm to 500 μm when attached to the container body 10.

Next, the configuration of the composite preform according to the present embodiment will be described with reference to FIG.

As shown in FIG. 3, the composite preform 70 includes a preform 10a made of a plastic material and an outer shrinking member 40 provided on the outside of the preform 10a.

Of these, the preform 10a includes a mouth portion 11a, a body portion 20a connected to the mouth portion 11a, and a bottom portion 30a connected to the body portion 20a. Of these, the mouth portion 11a corresponds to the mouth portion 11 of the container body 10 described above, and has substantially the same shape as the mouth portion 11.
Further, the body portion 20a corresponds to the neck portion 13, the shoulder portion 12 and the body portion 20 of the container body 10 described above, and has a substantially cylindrical shape. The bottom portion 30a corresponds to the bottom portion 30 of the container body 10 described above, and has a substantially hemispherical shape.

The outer shrinking member 40 is attached to the outer surface of the preform 10a without being adhered, and is in close contact with the preform 10a so as not to move or rotate. The outer shrinking member 40 is provided over the entire circumferential direction so as to surround the preform 10a, and has a circular horizontal cross section.

In this case, the outer shrinking member 40 is provided so as to cover the entire body portion 20a except for the portion 13a corresponding to the neck portion 13 of the container body 10 and the entire bottom portion 30a.

The outer shrinking member 40 may be provided in the entire area or a part of the area other than the mouth portion 11a. For example, the outer contracting member 40 may be provided so as to cover the entire body portion 20a and the bottom portion 30a except for the mouth portion 11a. Further, the number of outer shrinkage members 40 is not limited to one, and a plurality of outer shrinkage members 40 may be provided. For example, two outer contracting members 40 may be provided at two locations on the outer side of the body portion 20a.

The outer shrinking member 40 may have an action of shrinking with respect to the preform 10a. It is preferable that the outer shrinking member 40 shrinks (for example, heat shrinks) with respect to the preform 10a when an external action (for example, heat) is applied.

As the outer shrinking member 40, various materials can be used as described below.

For example, the outer shrinking member 40 may be made of the same material as the container body 10 (preform 10a). In this case, in the composite container 10A, for example, the outer shrinking member 40 can be arranged mainly in the portion where the strength is desired to be increased, and the strength of the portion can be selectively increased. For example, the outer shrinking member 40 may be provided around the shoulder portion 12 and the bottom portion 30 of the container body 10 to increase the strength of this portion. Examples of such a material include thermoplastic resins, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), and PEN (polyethylene naphthalate).

Further, the outer shrinking member 40 may be made of a material having a gas barrier property such as an oxygen barrier property or a water vapor barrier property. In this case, it is possible to improve the gas barrier property of the composite container 10A and prevent the content liquid from being deteriorated by oxygen or water vapor without using a multilayer preform or a preform containing a blend material as the preform 10a. For example, in the container body 10, the outer shrinking member 40 may be provided over the entire area of the shoulder portion 12, the neck portion 13, the body portion 20, and the bottom portion 30 to enhance the gas barrier property of this portion. As such a material, PE (polyethylene), PP (polypropylene), MXD-6 (nylon), or an oxygen absorber such as a fatty acid salt may be mixed with these materials.

Further, the outer shrinking member 40 may be made of a material having a light barrier property such as ultraviolet rays. In this case, it is possible to enhance the light barrier property of the composite container 10A and prevent the content liquid from being deteriorated by ultraviolet rays or the like without using a multilayer preform or a preform containing a blend material as the preform 10a. For example, in the container body 10, the outer shrinking member 40 may be provided over the entire area of the shoulder portion 12, the neck portion 13, the body portion 20, and the bottom portion 30 to enhance the ultraviolet barrier property of this portion. As such a material, a blended material or a material obtained by adding a light-shielding resin to PET, PE, or PP can be considered.

Further, the outer shrinking member 40 may be made of a material (material having low thermal conductivity) having higher heat retention or cold retention than the plastic material constituting the container body 10 (preform 10a). In this case, it is possible to make it difficult for the temperature of the content liquid to be transmitted to the surface of the composite container 10A without increasing the thickness of the container body 10 itself. As a result, the heat retention or cold retention of the composite container 10A is enhanced. For example, the outer shrinking member 40 may be provided on all or part of the body 20 of the container body 10 to improve the heat retention or cold retention of the body 20. Further, when the user grips the composite container 10A, it is prevented that the composite container 10A becomes difficult to hold due to being too hot or too cold. As such a material, foamed polyurethane, polystyrene, PE (polyethylene), PP (polypropylene), phenol resin, polyvinyl chloride, urea resin, silicone, polyimide, melamine resin and the like can be considered.

Further, the outer shrinking member 40 may be made of a material that is less slippery than the plastic material constituting the container body 10 (preform 10a). In this case, the user can easily grip the composite container 10A without changing the material of the container body 10. For example, the outer shrinking member 40 may be provided on all or part of the body 20 of the container body 10 to make it easier to hold the body 20.

Further, the outer shrinking member 40 may be pre-designed or printed. In this case, it is possible to display an image or characters on the composite container 10A without separately attaching a label or the like to the container body 10 after blow molding. For example, an outer shrinking member 40 may be provided on all or a part of the body 20 of the container body 10, and an image or characters may be displayed on the body 20. In this case, as the material of the outer shrinking member 40, the same material as the container body 10 may be used, or a material different from the container body 10 may be used.

Next, the blow molding method (manufacturing method of the composite container 10A) according to the present embodiment will be described with reference to FIGS. 4 (a) to 4 (g).

First, a preform 10a made of a plastic material is prepared (see FIG. 4A). In this case, for example, a preform 10a may be produced by an injection molding method using an injection molding machine (not shown).

Next, the outer shrinking member 40 is provided on the outer side of the preform 10a (see FIG. 4B). In this case, the outer contracting member 40 has a bottomed cylindrical shape as a whole, and has a cylindrical body portion 41 and a bottom portion 42 connected to the body portion 41. The outer shrinking member 40 is mounted so as to cover the entire body portion 20a except for the portion corresponding to the neck portion 13 of the container body 10 and the entire bottom portion 30a.

Next, the preform 10a and the outer shrinking member 40 are heated by the first heating device 55 (see FIG. 4C). At this time, the heating temperature of the preform 10a and the outer shrinking member 40 may be, for example, 50 ° C to 100 ° C.

When the outer shrinking member 40 is heated, the outer shrinking member 40 heat shrinks and comes into close contact with the outside of the preform 10a. As a result, a composite preform 70 having the preform 10a and the outer contracting member 40 in close contact with the outside of the preform 10a is obtained (see FIG. 4C).

In this way, a series of production of the composite preform 70 by heat-adhering the outer shrinking member 40 to the outside of the preform 10a in advance using the first heating device 55 to prepare the composite preform 70. The steps (FIGS. 4 (a) to (c)) and the series of steps (FIGS. 4 (d) to (g)) for producing the composite container 10A by blow molding are carried out at different places (factory, etc.). Becomes possible.

Next, the composite preform 70 is heated by the second heating device 51 (see FIG. 4D). At this time, the composite preform 70 is uniformly heated in the circumferential direction by the second heating device 51 while rotating with the mouth portion 11a facing downward. The heating temperature of the preform 10a and the outer shrinking member 40 in this heating step may be, for example, 90 ° C to 130 ° C.

Subsequently, the composite preform 70 heated by the second heating device 51 is sent to the blow molding die 50 (see FIG. 4E).

The composite container 10A is molded using the blow molding die 50. In this case, the blow molding die 50 includes a pair of body molds 50a and 50b that are separated from each other, and a bottom mold 50c (see FIG. 4E). In FIG. 4E, the pair of body molds 50a and 50b are open to each other, and the bottom mold 50c is raised upward. In this state, the composite preform 70 is inserted between the pair of body molds 50a and 50b.

Next, as shown in FIG. 4 (f), after the bottom mold 50c is lowered, the pair of body molds 50a and 50b are closed and sealed by the pair of body molds 50a and 50b and the bottom mold 50c. The blow-molded mold 50 is configured. Next, air is press-fitted into the preform 10a, and biaxial stretch blow molding is performed on the composite preform 70.

As a result, the container body 10 can be obtained from the preform 10a in the blow molding die 50. During this time, the body molds 50a and 50b are heated to 30 ° C to 80 ° C, and the bottom mold 50c is cooled to 5 ° C to 25 ° C. At this time, in the blow molding die 50, the preform 10a of the composite preform 70 and the outer shrinking member 40 are integrally expanded. As a result, the preform 10a and the outer shrinking member 40 are integrally formed into a shape corresponding to the inner surface of the blow molding die 50.

In this way, the composite container 10A including the container body 10 and the outer shrinking member 40 provided on the outer surface of the container body 10 is obtained.

Next, as shown in FIG. 4 (g), the pair of body molds 50a and 50b and the bottom mold 50c are separated from each other, and the composite container 10A is taken out from the blow molding mold 50.

As described above, according to the present embodiment, the preform 10a of the composite preform 70 and the outer shrinking member 40 are integrally formed by performing blow molding on the composite preform 70 in the blow molding mold 50. To prepare a composite container 10A having a container body 10 and an outer shrinking member 40. As a result, the preform 10a (container body 10) and the outer shrinking member 40 can be made of separate members. Therefore, various functions and characteristics can be freely imparted to the composite container 10A by appropriately selecting the type and shape of the outer shrinkage member 40.

Further, according to the present embodiment, when the composite container 10A is manufactured, a general blow molding apparatus can be used as it is, so that it becomes necessary to prepare a new molding facility for manufacturing the composite container 10A. Absent.

Examples Next, specific examples of the present embodiment will be described.

First, a preform 10a made of 18.3 g of PET single-layer preform was produced by an injection molding method.

Next, an outer shrinking member 40 was installed on the preform 10a, and these were heated to 80 ° C. to prepare a composite preform 70 having the preform 10a and the outer shrinking member 40. Subsequently, the composite preform 70 thus obtained was subjected to biaxial stretching blow molding to prepare a composite container 10A having a capacity of 180 mL.
Polyolefin was used as the outer shrinking member 40.

Modifications Next, modifications of the present invention will be described with reference to FIGS. 5, 6 and 7 (a) to 7 (g).

The modified examples shown in FIGS. 5, 6 and 7 (a) to 7 (g) do not have a body and a bottom as the outer shrinking member 40, but use a cylindrical outer shrinking member 40. .. As shown in FIG. 5, the outer shrinking member 40 extends from the shoulder portion 12 of the container body 10 to the lower portion of the body portion 20, but does not reach the bottom portion 30. Further, in the composite preform 70 shown in FIG. 6, the outer shrinking member 40 is in close contact so as to cover only the body portion 20a of the preform 10a, and more specifically, the neck portion 13 of the container body 10 of the body portion 20a. It covers the area excluding the portion 13a corresponding to the portion 13a and the portion corresponding to the lower portion of the body portion 20a.

The other configurations in FIGS. 5, 6 and 7 (a) to 7 (g) are substantially the same as the embodiments shown in FIGS. 1 to 4. In the modified examples shown in FIGS. 5, 6 and 7 (a) to 7 (g), the same parts as those of the embodiments shown in FIGS. 1 to 4 are designated by the same reference numerals, and detailed description thereof will be omitted.

In addition, the configuration and manufacturing method of the composite container 10A and the configuration and manufacturing method of the composite preform 70 are substantially the same as those of the embodiments shown in FIGS. 1 to 4, so detailed description thereof will be omitted.

10 Container body 10A Composite container 10a Preform 11 Mouth 11a Mouth 12 Shoulder 13 Neck 20 Body 20a Body 30 Bottom 30a Bottom 40 Outer shrinkage member 50 Blow molding mold 70 Composite preform

Claims (7)

In compound preform,
A preform made of a plastic material having a mouth, a body, and a bottom,
It comprises a tubular outer shrink member that is attached to the outside of the preform without being adhered.
A composite preform in which the outer shrinkable member has heat shrinkage and is in close contact with the outside of the preform so as to follow the shape of the preform. The composite preform according to claim 1, wherein the outer shrinking member is provided so as to cover a region of the body portion of the preform excluding a portion corresponding to the neck portion of the container body. The composite plastic according to claim 1, wherein the outer shrinking member is provided so as to cover the entire body of the preform except for the portion corresponding to the neck of the container body and the entire bottom of the preform. Remodeling. In the method of manufacturing composite preforms
The process of preparing a preform made of a plastic material having a mouth, a body, and a bottom,
A step of arranging a heat-shrinkable tubular outer shrinkage member on the outside of the preform,
By heating the outer shrinking member, the outer shrinking member is heat-shrinked so as to follow the shape of the preform, and the outer shrinking member is brought into close contact with the outside of the preform. Manufacturing method of composite preform. The method for manufacturing a composite preform according to claim 4, wherein the outer shrinking member is provided so as to cover a region of the body of the preform excluding a portion corresponding to the neck of the container body. The composite preform according to claim 4, wherein the outer shrinking member is provided so as to cover the entire area of the body portion of the preform except for the portion corresponding to the neck portion of the container body and the entire area of the bottom portion. Production method. A claim that the outer shrinking member is placed outside the preform in a step of arranging the outer shrinking member, with the longitudinal end of the outer shrinking member protruding from the bottom of the preform. The method for producing a composite preform according to any one of 4 to 6.

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