JP2018202699A - Production method of composite preform and production method of composite container - Google Patents

Abstract

To provide a production method of a composite preform which is used for production of a composite container comprising a container body and a plastic member for fully covering a bottom part of the container body, capable of preventing gassing between the container body and the plastic member caused by blow molding.SOLUTION: A production method of a composite preform 70 comprises: a step for preparing a preform 10a comprising a mouth part 11a, a trunk 20a coupled to the mount part 11a, and a bottom part 30a coupled to the trunk 20a; a step for preparing a tube-shaped heat-shrinkable plastic member 40 having a margin part for thermal compression bond on one end thereof; a step for fitting the preform 10a from the other end of the plastic member 40a; a step for heating the plastic member 40a and performing heat-shrinkage of the plastic member 40a; a step for performing thermal compression bond of the margin part of the plastic member 40a; and a step for twisting the margin part which has been subjected to the thermal compression bond for forming a twisted part 80.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a composite preform and a method for manufacturing a composite container.

  Recently, plastic bottles for storing content liquids such as foods and drinks have become common, and such plastic bottles store content liquids.

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

  By the way, in the conventional biaxial stretch blow molding method, for example, it is molded into a container shape using a preform including a single layer material such as PET (polyethylene terephthalate) or PP (polypropylene), a multilayer material or a blend material. However, in the conventional biaxial stretch blow molding method, the preform is generally simply formed into a container shape. For this reason, when various functions and characteristics (barrier property, heat retaining property, etc.) are given to the container, the means is limited, for example, by changing the material constituting the preform. In particular, it is difficult to have different functions and characteristics depending on the part of the container (for example, the trunk and the bottom).

  In the previous application (Japanese Patent Laid-Open No. 2015-128858), the present applicant has proposed a composite container that can impart various functions and characteristics to the container.

JP2015-128858A

The composite container disclosed in JP-A-2015-128858 is obtained by blow molding a composite preform including a container body and a plastic member.
The plastic member included in the composite preform is preferably heat-shrinkable from the viewpoint of adhesion to the preform, and thus the container body. However, plastic members having heat-shrinkability are tube-like due to their manufacturing method, so it is difficult to completely cover the bottom of the preform (container main body), and the light shielding property of the bottom is improved. It has been difficult to provide such a function to the bottom of the composite container.

Recently, the present inventors manufactured a composite container in which the bottom of a container body is completely covered with a plastic member by thermocompression bonding one end of a heat-shrinkable plastic member fitted with a preform. Found that you can.
Furthermore, the present inventors have found that the composite container obtained by the method including the twisting step is a container body resulting from blow molding as compared with the composite container obtained by the method including only the thermocompression bonding step not including the twisting step. It has been found that the generation of bubbles between the plastic member and the plastic member can be effectively prevented, and the occurrence of breakage such as peeling of the thermocompression bonding portion during blow molding can be prevented. .

  Accordingly, an object of the present invention is a method of manufacturing a composite preform used for manufacturing a composite container including a container body and a plastic member that can completely cover the bottom of the container body, and is caused by blow molding. It is an object of the present invention to provide a method for producing a composite preform that can prevent generation of bubbles between a container main body and a plastic member and damage of a thermocompression bonding portion.

The method for producing the composite preform of the present invention comprises:
Preparing a preform comprising a mouth, a body connected to the mouth, and a bottom connected to the body;
Preparing a tubular heat-shrinkable plastic member having a blank portion at one end for thermocompression bonding;
Fitting the preform from the other end of the plastic member;
Heating the plastic member and thermally shrinking the plastic member;
A step of thermocompression bonding the blank portion of the plastic member;
Twisting the thermocompression blank space and forming a twisted portion;
It is characterized by including.

  In the said aspect, it is preferable that the formation process of a twist part is performed so that the said margin part by thermocompression bonding may be threaded off.

  In the said aspect, it is preferable that a thermocompression bonding process and the formation process of a twist part are performed simultaneously.

  In the said aspect, it is preferable that the length of a margin part is 3 mm or more.

The method for producing the composite container of the present invention comprises:
The composite preform obtained by the above method is heated and inserted into a blow molding die, and the preform and the plastic member are integrally expanded by performing blow molding on the heated composite preform. And a step of causing the step to occur.

According to the method of the present invention, it is possible to provide a composite preform that can manufacture a composite container that includes a container body and a plastic member that can completely cover the bottom of the container body.
In addition, the composite container obtained using this composite preform can prevent bubbles from entering between the container body and the plastic member by blow molding, and the thermocompressed blank portion has It is possible to prevent breakage due to blow molding.

FIG. 1 is a front view of a composite preform produced by the method according to the present invention. FIG. 2 is a partial vertical sectional view showing a composite container produced using the composite preform of FIG. FIG. 3 is a horizontal cross-sectional view of the composite container shown in FIG. 2 taken along line III-III. FIG. 4 is a schematic view showing an embodiment of a method for producing a heat-shrinkable plastic member. FIG. 5 is a vertical sectional view showing a state in which the preform is fitted into a heat-shrinkable plastic member. FIG. 6 is a front view of a heat-shrinkable plastic member. FIG. 7 is a front view of the preform. FIG. 8 is a schematic view showing a method for manufacturing the composite container. FIG. 9 is a front view showing a crimping instrument having a holding part and a rotation mechanism used for thermocompression of a blank part and formation of a twisted part.

Composite preform 70
In one embodiment, as shown in FIG. 1, the composite preform 70 includes a preform 10a made of a plastic material and a heat-shrinkable plastic member 40a provided outside the preform 10a.

  A composite container 10A shown in FIG. 2 can be obtained by subjecting the composite preform 70 to biaxial stretch blow molding and inflating the preform 10a of the composite preform 70 and the plastic member 40a together.

Composite container 10A
As shown in FIG. 2, the composite container 10 </ b> A includes a container body 10 made of a plastic material located inside and a plastic member 40 provided in close contact with the outside of the container body 10.

  Among 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 trunk portion 20 provided below the shoulder portion 12, And a bottom portion 30 provided below the portion 20. In the present specification, “upper” and “lower” refer to the upper side and the lower side in a state where the composite container 10A is erected (FIG. 2), respectively.

  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, or may be a mouthpiece type mouth portion.

  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. The shoulder 12 is located between the neck 13 and the trunk 20 and has a shape whose diameter gradually increases from the neck 13 toward the trunk 20.

  Furthermore, the trunk | drum 20 has a cylindrical shape with 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 cylindrical shape such as a rectangular cylindrical shape or an octagonal cylindrical shape. Or the trunk | drum 20 may have a cylinder shape with a horizontal cross section which is not uniform toward upper direction from the downward direction. Moreover, in this Embodiment, although the unevenness | corrugation is not formed in the trunk | drum 20, and has a substantially flat surface, it is not restricted to this. For example, unevenness such as a panel or a groove may be formed on the body portion 20.

  The bottom portion 30 has a concave portion 31 located in the center and a grounding portion 32 provided around the concave portion 31. The shape of the bottom 30 is not particularly limited, and may have a conventionally known bottom shape (for example, a petaloid bottom shape or a round bottom shape).

  Moreover, although the thickness of the container main body 10 in the trunk | drum 20 is not limited to this, For example, it can be made thin to about 50 micrometers-250 micrometers. Further, the weight of the container body 10 is not limited to this, but for example, when the internal volume of the container body 10 is 500 ml, the weight can be 10 g to 20 g. Thus, by reducing the thickness of the container main body 10, the weight of the container main body 10 can be reduced.

  The container main body 10 can be manufactured by biaxially stretch blow molding a preform 10a manufactured by injection molding of a resin material.

  In order to enhance the barrier property of the container, a vapor deposition film such as a diamond-like carbon film or a silicon oxide thin film may be formed on the inner surface of the container body 10.

  The container main body 10 may consist of a bottle with a full capacity of 100 mL to 2000 mL, for example. Alternatively, the container main body 10 may be a large bottle having a full capacity of, for example, 10L to 60L.

  The heat-shrinkable plastic member 40 is in close contact with the outer surface of the container main body 10 in a thinly extended state, and is attached to the container main body 10 without being easily moved or rotated. As shown in FIG. 3, the heat-shrinkable plastic 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.

  As will be described later, the plastic member 40 is provided so as to surround the outside of the preform 10a, and after being brought into close contact with the outside of the preform 10a, the plastic member 40 is obtained by biaxial stretching blow molding together with the preform 10a. It is.

  As shown in FIG. 2, the plastic member 40 can be provided so as to cover the shoulder portion 12, the trunk portion 20, and the bottom portion 30 of the container body 10 except for the mouth portion 11 and the neck portion 13. With such a configuration, desired functions and characteristics can be imparted to the shoulder portion 12, the trunk portion 20, and the bottom portion 30 of the container body 10.

  Further, the thickness of the heat-shrinkable plastic member 40 is not limited to this, but can be set to, for example, about 5 μm to 50 μm in a state of being attached to the container body 10.

Further, since the heat-shrinkable plastic member 40 is not welded or bonded to the container body 10, it can be separated (separated) from the container body 10 and removed.
As a method of separating (peeling) the heat-shrinkable plastic member 40 from the container body 10, for example, the heat-shrinkable plastic member 40 is cut using a blade or the like, or cut into the heat-shrinkable plastic member 40 in advance. A line may be provided, and the heat-shrinkable plastic member 40 may be peeled along the cutting line. Since the heat-shrinkable plastic member 40 can be separated and removed from the container body 10 by the method as described above, the colorless and transparent container body 10 can be recycled as in the conventional case.

Manufacturing method of composite preform 70 The manufacturing method of the composite preform 70 according to the present invention includes:
Preparing a preform 10a including a mouth portion 11a, a trunk portion 20a coupled to the mouth portion 11a, and a bottom portion 30a coupled to the trunk portion 20a;
Preparing a tubular heat-shrinkable plastic member 40a having a blank portion 80a at one end for thermocompression bonding;
A step of fitting the preform 10a from the other end of the plastic member 40a;
Heating the plastic member 40a and thermally shrinking the plastic member 40a;
A step of thermocompression bonding the blank portion 80a of the plastic member 40a;
Twisting the heat-pressed blank portion 80a to form the twisted portion 80;
including.
Hereinafter, each step will be described in detail.

Process for Preparing Preform 10a As shown in FIG. 1, 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 11 a corresponds to the mouth portion 11 of the container body 10 described above, and has substantially the same shape as the mouth portion 11. Moreover, the trunk | drum 20a respond | corresponds to the neck part 13, the shoulder part 12, and the trunk | drum 20 of the container main body 10 mentioned above, and has a substantially cylindrical shape. The bottom 30a corresponds to the bottom 30 of the container body 10 described above, and has a substantially hemispherical shape.

The preform 10a can be manufactured by injection-molding a resin material using a conventionally known apparatus.
As the resin material, it is preferable to use a thermoplastic resin, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PC (polycarbonate), or ionomer. Moreover, you may blend and use the various resin mentioned above.
In addition, the preform 10a may contain colorants such as red, blue, yellow, green, brown, black, and white. However, in consideration of ease of recycling, the preform 10a does not contain these colorants and is colorless. It is preferably transparent.

Moreover, the container main body 10 can be made into the multilayer molding bottle of 2 layers or more by producing the multilayer preform 10a of 2 layers or more by injection molding.
For example, the intermediate layer includes a resin (intermediate layer) having gas barrier properties and light shielding properties such as MXD6, MXD6 + fatty acid salt, PGA (polyglycolic acid), EVOH (ethylene vinyl alcohol copolymer) or PEN (polyethylene naphthalate) A multilayer molded bottle having gas barrier properties, light-shielding properties, and the like can be obtained by forming a preform 10a consisting of three or more layers as a layer and then blow-molding. As the intermediate layer, a resin blended with the various resins described above may be used.

  Further, by mixing an inert gas (nitrogen gas, argon gas) with the thermoplastic resin melt, a foam preform having a foam cell diameter of 0.5 to 100 μm is formed, and this foam preform is blow-molded. Thus, the container body 10 may be manufactured. Since such a container main body 10 contains the foam cell, the light shielding property of the container main body 10 whole can be improved.

Process for Preparing Tube-shaped Heat-Shrinkable Plastic Member 40a In one embodiment, the tube-shaped heat-shrinkable plastic member 40a can be produced by a method including an extrusion process.
More specifically, first, a resin material or the like to be described later is heated and melted in an extrusion apparatus, and the molten resin material or the like is continuously extruded from a ring die and cooled to be formed into an unstretched extruded tube 1. (See FIG. 4 (a)). The multilayer plastic member 40a can be manufactured by co-extruding two or more resin materials.
Next, one end of the extruded tube is closed by welding or bonding one end of the unstretched extruded tube.
Further, the extruded tube 1 whose one end is closed is disposed in a mold 2 having an inner diameter larger than the outer diameter of the extruded tube 1 (see FIG. 4B).
Next, the blow device 3 is disposed (attached) to the other end of the extruded tube 1 (see FIG. 4C). At this time, it is preferable that the blower 3 is in close contact with the extruded tube 1 so that air does not leak between them.
Subsequently, the extruded tube 1, the mold 2 and the blow device 3 are sent to the heating furnace 4 in this arrangement, and heated to 70 to 150 ° C. inside the heating furnace 4 (see FIG. 4D). As the heating furnace 4, a hot-air circulating heating furnace may be used in order to make the inside uniform. Or you may heat these by passing the extrusion tube 1, the metal mold | die 2, and the blow apparatus 3 in the heated liquid.
Next, the extruded tube 1, the mold 2 and the blow device 3 are taken out from the heating furnace 4, and air is blown into the extruded tube 1 from the blow device 3, whereby the inner surface of the extruded tube 1 is stretched under pressure. As a result, the extruded tube 1 expands and expands along the inner shape of the mold 2 (see FIG. 4E).
Thereafter, the extruded tube 1 is cooled in cold water while air is blown out from the blower 3, and the extruded tube is taken out from the mold 2 (see FIG. 4 (f)). By cutting this into a desired size, a tubular heat-shrinkable plastic member 40a is obtained (see FIG. 4G).
A commercially available tube-shaped heat-shrinkable plastic member 40a may be used.

The length of the heat-shrinkable plastic member 40a is longer than the length of the preform 10a, and has a blank portion 80a at one end thereof as shown in FIG. The length of the blank portion 80a is preferably 3 mm or more, and more preferably 5 mm or more and 20 mm or less. By setting the length of the blank portion 80a within the above numerical range, the thermocompression bonding step and the step of twisting the blank portion 80a can be performed more easily, and the material to be used can be reduced and the cost can be reduced. it can.
As shown in FIG. 6, the length of the heat-shrinkable plastic member 40a refers to the length X before the heat shrinkage and including the blank portion 80a. Moreover, the length of the preform 10a means the length Y from the neck part 13a to the bottom part 30a, as FIG. 7 shows.

The plastic member 40a is made of, for example, PE, PP, PET, PEN, poly-4-methylpentene-1, polystyrene, AS resin, ABS tree, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, Polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, ionomer resin, diallyl phthalate resin, fluorine resin, polymethyl methacrylate, polyacrylic acid, polymethyl acrylate, polyacrylonitrile, polyacrylamide, polybutadiene, polybutene-1, polyisoprene, Polychloroprene, ethylene propylene rubber, butyl rubber, nitrile rubber, acrylic rubber, silicone rubber, fluorine rubber, nylon 6, nylon 6,6, MXD6, aromatic polyamide, polycarbonate, polyterephthalate Acid ethylene, polybutylene terephthalate, ethylene polynaphthalene, U polymer, liquid crystal polymer, modified polyphenylene ether, polyetherketone, polyetheretherketone, unsaturated polyester, alkyd resin, polyimide, polysulfone, polyphenylene sulfide, polyethersulfone, Silicone resin, polyurethane, phenol resin, urea resin, polyethylene oxide, polypropylene oxide, polyacetal, epoxy resin and the like can be included.
Among these, PE, PP, and polystyrene are preferable because damage from a thermocompression-bonded portion, which will be described later, can be prevented during blow molding in manufacturing the composite container 10A.
The resin material may include a copolymer obtained by polymerizing two or more monomer units constituting the above-described resin. Furthermore, the resin material may comprise two or more of the above-described resins.

The heat-shrinkable plastic member 40a may include a material having a gas barrier property such as an oxygen barrier property or a water vapor barrier property.
In this case, without using a multi-layer preform or a preform containing a blend material as the preform 10a, the gas barrier property of the composite container 10A is improved, oxygen is prevented from entering the container, and the content liquid is prevented from deteriorating. In addition, it is possible to prevent the evaporation of water vapor from the inside of the container to the outside and to prevent the internal volume from decreasing.
As such a material, PE, PP, MXD-6, PGA, EVOH, PEN, or an oxygen absorbing material such as a fatty acid salt may be mixed with these materials.
When the heat-shrinkable plastic member 40a is composed of multiple layers, a layer made of a material having gas barrier properties may be provided.

The heat-shrinkable plastic member 40a may contain a material having a light barrier property such as ultraviolet rays.
In this case, the light barrier property of the composite container 10A can be improved and the content liquid can be prevented 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.
As such a material, a resin material containing two or more kinds of the above-described resins, or a material obtained by adding a light-shielding resin to PET, PE, or PP can be considered. Moreover, you may use the foaming member with the foam cell diameter of 0.5-100 micrometers produced by mixing inert gas (nitrogen gas, argon gas) with the melt of a thermoplastic resin.
When the heat-shrinkable plastic member 40a is composed of multiple layers, a layer made of a material having a light barrier property may be provided.

Further, the heat-shrinkable plastic member 40a may include a material having a higher heat retaining property or a higher heat retaining property than the plastic material forming the preform 10a (a material having a low heat conductivity).
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. Thereby, the heat retaining property or cold retaining property of the composite container 10A is enhanced.
Examples of such materials include foamed polyurethane, polystyrene, PE, PP, phenol resin, polyvinyl chloride, urea resin, silicone, polyimide, melamine resin, and the like.
In the case where the heat-shrinkable plastic member 40a is composed of multiple layers, it may be provided with a layer made of a material having high heat retention or cold retention (material having low thermal conductivity).
Moreover, it is preferable to mix a hollow particle with the resin material containing these resins. The average particle diameter of the hollow particles is preferably 1 to 200 μm, and more preferably 5 to 80 μm. The hollow particles may be organic hollow particles composed of a resin or the like, or may be inorganic hollow particles composed of glass or the like. Hollow particles are preferred. Examples of the resin constituting the organic hollow particles include styrene resins such as cross-linked styrene-acrylic resins, (meth) acrylic resins such as acrylonitrile-acrylic resins, phenolic resins, fluorine resins, polyamide resins, and polyimides. Resin, polycarbonate resin, polyether resin and the like. Also, Ropeke HP-1055, Ropeke HP-91, Ropeke OP-84J, Ropeke Ultra, Ropeke SE, Ropeke ST (manufactured by Rohm and Haas), Nipol MH-5055 (manufactured by Nippon Zeon), SX8782 Commercially available hollow particles such as SX866 (manufactured by JSR Corporation) can also be used.
As content of a hollow particle, when the heat-shrinkable plastic member 40a consists of a single layer, it is 0.01-50 mass parts with respect to 100 mass parts of resin materials contained in the heat-shrinkable plastic member 40a. It is preferable that it is 1 to 20 parts by mass. When the heat-shrinkable plastic member 40a is composed of multiple layers, the heat-shrinkable plastic member 40a is 0.01 to 50 parts by mass with respect to 100 parts by mass of the resin material contained in the layer of the heat-shrinkable plastic member 40a containing the hollow particles. It is preferable that it is 1 to 20 parts by mass.

The heat-shrinkable plastic member 40a may include a material that is less slippery than the plastic material that forms the preform 10a.
In this case, the user can easily hold the composite container 10A without changing the material of the container body 10. Note that when the heat-shrinkable plastic member 40a is composed of multiple layers, the preform 10a is configured. You may provide the layer which consists of material which is harder to slip than a plastic material. In this case, the layer is preferably the outermost layer of the heat-shrinkable plastic member 40a.

Further, the heat shrinkable plastic member 40a may be designed or printed. In this case, it is possible to display images and characters on the composite container 10A without separately providing a label or the like to the container body 10 after blow molding.
Printing can be performed by a printing method such as an inkjet method, a gravure printing method, an offset printing method, or a flexographic printing method. For example, when the inkjet method is used, a print layer can be formed by applying UV curable ink to the heat-shrinkable plastic member 40a (40), irradiating it with UV, and curing it.
This printing may be performed on the heat-shrinkable plastic member 40a before being fitted into the preform 10a, or may be performed in a state where the heat-shrinkable plastic member 40a is provided outside the preform 10a. good. Further, the heat-shrinkable plastic member 40 of the composite container 10A after blow molding may be printed.

As shown in FIG. 6, the method of the present invention includes a step of fitting the preform 10a from the end of the heat-shrinkable plastic member 40a opposite to the side where the blank portion 80a is provided.

Heat Shrink Step The method of the present invention includes a step of heating and shrinking the heat shrinkable plastic member 40a.

  The method for heating the heat-shrinkable plastic member 40a is not particularly limited, and can be appropriately performed using infrared rays, hot air, or the like. The heating temperature is preferably 60 ° C. or higher and 250 ° C. or lower, and more preferably 80 ° C. or higher and 150 ° C. or lower. The heating temperature is the surface temperature of the heat-shrinkable plastic member 40a at the time of heating, not the irradiation temperature of infrared rays or warm air.

  The heat-shrinkable plastic member 40a after heat shrinkage is not adhered to the outer surface of the preform 10a and is in close contact with the preform 10a so that it does not move or rotate, or does not fall by its own weight. It is in close contact.

Thermocompression-bonding process The method of the present invention includes a process of thermocompression-bonding the blank portion 80a of the plastic member 40a, whereby the bottom of the tubular plastic member 40a can be formed.

  The method of thermocompression bonding the margin 80a is not particularly limited, and is not particularly limited as long as it can be crimped by inserting a margin heated by infrared rays or warm air. Or a heat-resistant resin tool (hereinafter, referred to as “crimping tool” in some cases) may be used, or they may be combined.

  The surface of the crimping device may be flat or partially or entirely uneven.

  The crimping instrument may have a heating mechanism on its surface. Thereby, the crimping | compression-bonding strength of the blank part 80a can be raised more. The heating temperature of the surface of the crimping device is preferably, for example, 100 ° C. or more and 250 ° C. or less.

The pressure during pressure bonding is preferably 50 N / cm ² or more and 1000 N / cm ² or less, more preferably 100 N / cm ² or more and 500 N / cm ² or less.

  The temperature of the heat-shrinkable plastic member 40a at the time of pressure bonding is preferably 80 ° C. or higher and 200 ° C. or lower, although it depends on the material.

Twist part 80 formation process The method of this invention comprises the process of twisting the margin part 80a which carried out the thermocompression bonding, and forming the twist part 80 shown in FIG.
As a result, it is possible to prevent bubbles from being generated between the container body 10 and the plastic member 40 included in the composite container 10A after blow molding, and the blank portion 80a that has been thermocompression bonded by blow molding is peeled off. It can be prevented from being damaged.
Moreover, the plastic member 40 provided with the bottom part which has a favorable external appearance can be obtained by twisting the blank part 80a and blow-molding the plastic member 40a in which the twisted part 80 is formed.

The method for forming the twisted portion 80 is not particularly limited, and can be performed by manually twisting the blank portion 80a using an instrument such as pliers.
Moreover, it can carry out mechanically using the rotation apparatus etc. which contain the holding | maintenance part and rotation part which hold | maintain the preform 10a and the plastic member 40a.
Also, a method combining these may be used. Specifically, the torsion part 80a is sandwiched by using a tool such as pliers and the preform 10a and the plastic member 40a are rotated by the rotating part. 80 can be formed.

In one embodiment, the twisted portion 80 can be formed simultaneously with the thermocompression bonding of the blank portion 80a. Thereby, a work process can be reduced and productivity can be improved more.
Specifically, it can be performed by providing a rotation mechanism in the crimping tool, fixing the preform 10a and the plastic member 40a to the holding portion, and rotating the crimping tool.
It can also be performed by using the crimping tool as a holding part and rotating the preform 10a and the plastic member 40a by the rotating part.
The degree to which the blank portion 80a is twisted is not particularly limited, and may be a degree of rotation by 0.25 to 30 or may be performed until the thread is broken, but the appearance may be improved. Since it can prevent more effectively that the part which carried out thermocompression bonding and it will damage by blow molding, it is preferable to carry out until it cuts off.

Manufacturing method of composite container 10A The manufacturing method of the composite container 10A according to the present invention includes:
Heating the composite preform 70 produced as described above and inserting it into a blow mold;
And a step of expanding the preform 10a and the heat-shrinkable plastic member 40a integrally by performing blow molding on the composite preform 70 after heating.

  8A to 8D, the manufacturing method of the composite container 10A of the present invention will be described in more detail.

First, the composite preform 70 is heated by the heating device 51 (see FIG. 8A). At this time, the composite preform 70 is evenly heated in the circumferential direction by the heating device 51 while rotating with the mouth portion 11a facing downward. The heating temperature of the preform 10a and the plastic member 40a in this heating step may be, for example, 90 ° C. to 130 ° C.
The heating device 51 may generate warm air or irradiate infrared rays.

  Subsequently, the composite preform 70 heated by the heating device 51 is sent to the blow molding die 50 (see FIG. 8B).

  The composite container 10 </ b> A is molded using this blow molding die 50. In this case, the blow mold 50 includes a pair of body molds 50a and 50b and a bottom mold 50c that are divided from each other (see FIG. 8B). In FIG. 8B, 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. 8C, after the bottom mold 50c is lowered, the pair of body molds 50a and 50b are closed, and the pair of body molds 50a and 50b and the bottom mold 50c are used. A sealed blow molding die 50 is configured. Next, air is press-fitted into the preform 10 a and biaxial stretch blow molding is performed on the composite preform 70.

  As a result, the container body 10 is obtained from the preform 10 a 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 mold 50, the preform 10a of the composite preform 70 and the plastic member 40a are expanded as a unit. Thereby, the preform 10a and the plastic member 40a are integrally formed into a shape corresponding to the inner surface of the blow mold 50.

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

  Next, as shown in FIG. 8 (d), the pair of body molds 50 a and 50 b and the bottom mold 50 c are separated from each other, and the composite container 10 </ b> A is taken out from the blow mold 50.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

(Step of preparing the preform 10a)
A PET preform 10a shown in FIG. 7 was produced using an injection molding machine. The weight of this preform 10a was 23.8 g, and its length Y was 90 mm.

(Process for preparing the heat-shrinkable plastic member 40a)
The polyolefin resin was melted and extruded from a ring die. Subsequently, the extruded tube inner surface was pressurized or the tube outer surface was subjected to negative pressure from the inner surface to expand the diameter, thereby producing a heat-shrinkable plastic member 40a shown in FIG.
The length X of the manufactured heat-shrinkable plastic member 40a was 100 mm, and the length of the blank portion 80a was 10 mm.

(Fitting process)
Next, the preform 10a was fitted by hand from the end opposite to the blank portion 80a of the heat-shrinkable plastic member 40a.

(Heat shrinkage and thermocompression bonding process, torsion part 80 forming process)
After the fitting, the preform 10a and the heat-shrinkable plastic member 40a were heated to 100 ° C. by using an infrared heater to heat-shrink the heat-shrinkable plastic member 40a.
Next, the preform 10a and the plastic member 40a are fixed to the holding portion 81 shown in FIG. 9, and the marginal portion 80a is 300 N / cm using the crimping tools 82 and 83 having the rotating mechanism shown in FIG. ^The film was sandwiched at a pressure of ² and subjected to thermocompression bonding. Further, the preform 10a and the plastic member 40a were rotated by the rotating mechanism until the crimped blank portion 80a was threaded and the twisted portion 80 was formed.

(Manufacture of composite containers)
The composite preform 70 obtained as described above was heated to 100 ° C. using an infrared heater and conveyed to a blow mold shown in FIG. 8b. In this blow molding die, the composite preform 70 was blow-molded to obtain a composite container 10A having a full injection capacity of 500 mL. In this composite container 10A, the container body 10 was covered with the plastic member 40 up to the bottom. In addition, no bubbles were observed between the container body 10 and the plastic member 40.

Claims (7)

Preparing a preform comprising a mouth, a body connected to the mouth, and a bottom connected to the body;
Preparing a tubular heat-shrinkable plastic member having a blank portion at one end for thermocompression bonding;
A step of fitting the preform from the other end of the plastic member;
Heating the plastic member and thermally shrinking the plastic member;
Thermocompression bonding the blank portion of the plastic member;
Twisting the thermobonded blank part, forming a twisted part;
A method for producing a composite preform, comprising:   The method according to claim 1, wherein the step of forming the twisted portion is performed so as to thread the blank portion that has been thermocompression bonded.   The method according to claim 1 or 2, wherein the thermocompression bonding step and the twisted portion forming step are performed simultaneously.   The method according to claim 1, wherein a length of the blank portion is 3 mm or more. Heating the composite preform obtained by the method according to any one of claims 1 to 4 and inserting it into a blow mold; and
A method for producing a composite container, comprising: performing a blow molding on the composite preform after heating, and expanding the preform and the plastic member integrally.   The composite preform obtained by the method as described in any one of Claims 1-4.   A composite container obtained by the method according to claim 5.