JP2016215582A - Composite preform - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite preform free from the breakage of a cylindrical shrinkable tube upon use.SOLUTION: Provided is a composite preform 70 having: a preform 10a; and a cylindrical preform 40a. in the shrinkage tube 40a of the composite preform 70, thickness before shrinkage is 0.2 to 0.5 mm.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a composite preform.

  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, a preform including a single layer material such as PET or PP, a multilayer material, a blend material, or the like is used to form a container shape. 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).

  By the way, a technique has been developed in which a composite preform is prepared in advance by inserting a cylindrical shrinkable tube outside the preform, and blow molding is performed on the composite preform. Further, in such a composite preform, there is a demand for a durable tube that does not break during use.

JP 2009-241526 A

  The present invention has been made in consideration of these points, and is a composite preform manufactured by inserting a cylindrical shrinkable tube into a preform, and the shrinkable tube breaks during use. The object is to provide a composite preform that does not occur.

  The present invention relates to a composite preform, a preform having a mouth portion, a preform body, and a flange portion provided between the mouth portion and the preform body, and a cylindrical shape inserted into the preform. A shrinkable tube, wherein the shrinkable tube has a thickness before shrinkage of 0.2 to 0.5 mm.

In the present invention, when the height of the preform body is A, the height B of the shrink tube before shrinkage is
B = A × (0.90-1.00)
It is a composite preform characterized by becoming.

  The present invention is the composite preform characterized in that a gap between the shrinkable tube and the flange portion is 1 mm or less after shrinkage.

The present invention is a composite container obtained by biaxially stretching blow molding the composite preform described above.

The present invention is a shrinkable tube used for the composite preform described above.

The present invention is a preform used for the composite preform described above.

  According to the present invention, a highly accurate composite preform is obtained in which the shrinkable tube does not break during use.

FIG. 1 shows a composite preform manufacturing system according to an embodiment of the present invention. FIG. 2 is a vertical sectional view showing the composite preform. FIG. 3 is a view showing the bottom of the composite preform. FIG. 4 is a diagram showing a process of inserting a cylindrical shrinkable tube into a preform. FIG. 5 is a diagram showing a process of inserting a cylindrical shrinkable tube into a preform. FIG. 6 is a partial vertical sectional view showing the composite container. FIG. 7 is a horizontal sectional view showing the composite container.

<Embodiment of the Invention>
Embodiments of the present invention will be described below with reference to the drawings. 1 to 7 are diagrams showing an embodiment of the present invention.

  First, an outline of a composite container obtained by blow molding using a composite preform will be described with reference to FIGS. 6 and 7. 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. 6), respectively.

  The composite container 10A shown in FIG. 6 and FIG. 7 is 2 with respect to the composite preform 70 (see FIG. 2) including a preform 10a and a plastic member (also referred to as a cylindrical shrinkable tube) 40a using a blow mold. By performing axial stretch blow molding, the preform 10a of the composite preform 70 and the plastic member 40a are integrally expanded. In addition, the composite liquid 10 </ b> A is filled with the content liquid L to obtain a composite container 10 </ b> B containing the content liquid.

  Such a composite container 10 </ b> A includes a container body 10 made of a plastic material located inside, and a plastic member (cylindrical contraction tube) 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.

  On the other hand, the 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.

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

  Of these, the mouth portion 11 includes a screw portion 14 screwed into 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. 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.

  On the other hand, 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 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.

  Such a container main body 10 can be manufactured by biaxially stretching blow-molding a preform 10a (described later) manufactured by injection molding a synthetic resin material. As the material of the preform 10a, that is, the container body 10, a thermoplastic resin, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or PC (polycarbonate) may be used. preferable. Moreover, you may blend and use the various resin mentioned above. Further, 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 in order to enhance the barrier property of the container.

  The container body 10 can also be formed as a multilayer molded bottle having two or more layers. That is, by extrusion molding or injection molding, for example, the intermediate layer has 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). You may form as a multilayer bottle which has gas barrier property and light-shielding property by extrusion-molding preform 10a which consists of three or more layers as resin which it has (intermediate layer), and carrying out blow molding. As the intermediate layer, a resin obtained by blending the above-described various resins 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.

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

  Next, the plastic member 40 made of a cylindrical shrinkable tube will be described. As will be described later, the plastic member 40 (40a) is inserted so as to surround the outer side of the preform 10a, and after being in close contact with the outer side of the preform 10a, the plastic member 40 (40a) is obtained by biaxial stretching blow molding together with the preform 10a. It is what was done.

  The plastic member 40 is attached to the outer surface of the container body 10 without being bonded, and is in close contact with the container body 10 so as not to move or rotate. The plastic member 40 is thinly extended on the outer surface of the container body 10 to cover the container body 10. As shown in FIG. 2, the 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.

  In this case, the plastic member 40 is provided so as to cover the shoulder portion 12, the neck portion 13, the trunk portion 20, and the bottom portion 30 except for the mouth portion 11 and the flange 17 in the container body 10. Thereby, desired functions and characteristics can be imparted to the shoulder portion 12, the neck portion 13, the trunk portion 20, and the bottom portion 30 of the container body 10.

  As such a plastic member 40a, a cylindrical contraction tube having an effect of contracting with respect to the preform 10a can be used.

  The plastic member (cylindrical shrinkable tube) 40a has a function of contracting with respect to the preform 10a, is provided outside the preform 10a, is heated integrally with the preform 10a, and is biaxially stretch blow molded. Is done. Such a plastic member 40a is thermally contracted with respect to the preform 10a when an external action (for example, heat) is applied.

  The thickness of the plastic members 40a, 40 is not limited to this, but is 0.2 to 0.5 mm thick before being inserted into the preform 10a, and is inserted into the preform 10a. The thickness is 0.4 to 1.0 mm after being thermally contracted, and preferably 0.04 to 0.20 mm when attached to the container body 10 after blow molding. Thus, since the thickness of the plastic member 40 is 0.04 to 0.20 mm when attached to the container body 10, the vending machine can handle the composite container 10B containing the content liquid in the vending machine. The plastic member 40 is not broken, and the vending machine characteristics of the plastic member 40 can be enhanced.

  Next, the structure of the composite preform will be described with reference to FIG.

  As shown in FIG. 2, the composite preform 70 includes a preform 10a made of a plastic material and a plastic member 40a made of a cylindrical shrinkable tube provided outside the preform 10a.

  Among 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 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 10 a is formed between the mouth portion 11 a and the body portion 20 a and has a flange portion 17 a corresponding to the flange portion 17 of the container body 10. Further, the preform body 20A is constituted by the body portion 20a and the bottom portion 30a of the preform 10a.

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

  The plastic member 40a may be provided in the entire region or a partial region other than the mouth portion 11a and the flange portion 17a. For example, the plastic member 40a may be provided so as to cover the entire body portion 20a and the bottom portion 30a except for the mouth portion 11a and the flange portion 17a. Furthermore, the number of plastic members 40a is not limited to one, and a plurality of plastic members 40a may be provided. For example, two plastic members 40a may be provided at two locations outside the trunk portion 20a.

  As such a plastic member 40a, a cylindrical shrinkable tube that is thermally shrunk with respect to the preform 10a as described above is used.

  Examples of the plastic member 40a include polyethylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, poly-4-methylpentene-1, polystyrene, AS resin, ABS tree, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, Polyvinyl alcohol, polyvinyl acetal, polyvinyl butyral, diallyl phthalate resin, fluororesin, polymethyl methacrylate, polyacrylic acid, polymethyl acrylate, polyacrylonitrile, polyacrylamide, polybutadiene, polybutene-1, polyisoprene, polychloroprene, Ethylene propylene rubber, butyl rubber, nitrile rubber, acrylic rubber, silicone rubber, fluoro rubber, nylon 6, nylon 6,6, nylon MXD6, aromatic poly , Polycarbonate, ethylene polyterephthalate, polybutylene terephthalate, poly ethylene naphthalate, U polymer, liquid crystal polymer, modified polyphenylene ether, polyether ketone, polyether ether ketone, unsaturated polyester, alkyd resin, polyimide, polysulfone, polyphenylene Examples thereof include sulfide, polyethersulfone, silicone resin, polyurethane, phenol resin, urea resin, polyethylene oxide, polypropylene oxide, polyacetal, and epoxy resin. Among these, it is preferable to use thermoplastic inelastic resins such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN). Moreover, those blend materials, multilayer structures, and partial multilayer structures may be used. Also, by mixing an inert gas (nitrogen gas, argon gas) with a melt of a thermoplastic resin, a foam member having a foam cell diameter of 0.5 to 100 μm is used, and this foam preform is molded. , The light shielding property can be improved.

  The plastic member 40a 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 plastic member 40 can be intensively arranged at a portion where the strength is to be increased, and the strength of the portion can be selectively increased. For example, plastic members 40 may be provided around the shoulder 12 and the bottom 30 of the container body 10 to increase the strength of this portion. Examples of such materials include thermoplastic resins, particularly PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), and PC (polycarbonate).

  The plastic member 40a 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, the gas barrier property of the composite container 10A can be enhanced without using a multilayer preform or a preform containing a blend material as the preform 10a, and the content liquid can be prevented from being deteriorated by oxygen or water vapor. For example, a plastic member 40 may be provided in the entire region of the shoulder portion 12, the neck portion 13, the trunk portion 20, and the bottom portion 30 of the container body 10, and the gas barrier property of this portion may be improved. As such a material, PE (polyethylene), PP (polypropylene), MXD-6 (nylon), EVOH (ethylene vinyl alcohol copolymer) or an oxygen absorbing material such as a fatty acid salt may be mixed with these materials. It is done.

  The plastic member 40a may be made of 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. For example, a plastic member 40a may be provided in the entire region of the shoulder portion 12, the neck portion 13, the trunk portion 20, and the bottom portion 30 of the container body 10 to enhance the ultraviolet barrier property of this portion. As such a material, a blend material 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.

  Moreover, the plastic member 40a may be made of a material (a material having a low thermal conductivity) having a higher heat retaining property or a lower heat retaining property than a 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. Thereby, the heat retaining property or cold retaining property of the composite container 10A is enhanced. For example, the plastic member 40 may be provided on the whole or a part of the body 20 in the container body 10 to enhance the heat retaining property or the cold retaining property 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. Examples of such materials include foamed polyurethane, polystyrene, PE (polyethylene), PP (polypropylene), phenol resin, polyvinyl chloride, urea resin, silicone, polyimide, melamine resin, and the like. 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.

  The plastic member 40a may be made of a material that is less slippery than the plastic material that constitutes the container body 10 (preform 10a). In this case, the user can easily hold the composite container 10 </ b> A without changing the material of the container body 10. For example, a plastic member 40 may be provided on all or part of the body 20 of the container body 10 so that the body 20 can be easily held.

  Further, the 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. For example, the plastic member 40 may be provided on all or part of the trunk 20 in the container body 10, and images or characters may be displayed on the trunk 20. In this case, the material of the plastic member 40 may be the same as that of the container body 10 or may be different from that of the container body 10.

  In addition, the plastic member 40a may include a pigment and a pigment dispersant that give the plastic member 40a a desired color. Furthermore, the adhesion between the preform 10a and the plastic member 40a can be improved by mixing the Si-based additive into the plastic member 40a.

  Next, the shape of the plastic member 40a will be described.

  As shown in FIGS. 4 and 5, the plastic member 40a is formed of a shrinkable tube having a cylindrical shape as a whole, for example, an extruded tube. Such a plastic member 40a is inserted into the outside of the preform body 20A of the preform 10a (see FIG. 5), and by heating the plastic member 40a, the plastic member 40a contracts and the preform 10a is preformed. It closely adheres to the outer surface of the reform main body 20A. In this way, as shown in FIG. 2, a composite preform 70 having the preform 10a and the plastic member 40a is obtained.

As shown in FIGS. 4 and 5, when the height of the preform body 20A of the preform 10 is A and the height of the plastic member 40a before shrinking is B,
B = A × (0.90-1.00)
It has become.

  Here, since the preform body 20A of the preform 10 includes the body portion 20a and the bottom portion 30a, the height of the preform body 20A is the distance from the funged portion 17a to the bottom portion 30a.

  Further, when the plastic member 40a is inserted into the preform 10a and heated and thermally contracted as described above, the plastic member 40a is in close contact with the preform 10a, and thus the composite preform 70 is obtained. In this case, the plastic member 40a has an outer surface 40A and contracts inward on the bottom 30a side of the preform 10a to have a bottom edge 40B.

Next, a composite preform manufacturing system will be described with reference to FIG.
As shown in FIG. 1, the composite preform manufacturing system includes a preform supply unit 50 that supplies the preform 10a in an upright state, and an inversion unit 51 that inverts the preform 10a supplied from the preform supply unit 50. Then, a shrinkable tube insertion portion 52 for inserting a plastic member 40a made of a cylindrical shrinkable tube from above into a preform 10a which is reversed by the reversing portion 51 and the bottom portion 30a faces upward and the mouth portion 11a faces downward. And.

  Thus, the composite preform 70 is obtained by inserting the plastic member 40a into the preform 10a. Next, the composite preform 70 is traveled by a travel chain 58 spanned between the wheel 56 and the wheel 57. Also, on one side of the running chain 58, there is provided a heating portion 53 made of an infrared heater that heats and contracts the plastic member 40a and closely contacts the plastic member 40a to the preform 10a.

  Thus, the plastic member 40a can be adhered to the preform 10a by heating and shrinking the plastic member 40a (see FIG. 2).

  The composite preform 70 obtained in this way is cooled by the cooling unit 54 provided on the other side of the traveling chain 58 and sent to the inspection unit 60.

  The inspection unit 60 observes the composite preform 70 from the side surface, and inspects the length C of the gap between the flange portion 17 of the preform 10a and the plastic member 40a, and the composite preform 70. Is observed from the bottom 30a side and has a second imaging unit 62 for performing a centering inspection between the plastic member 40a and the preform 10a.

  Further, on the downstream side of the inspection unit 60, an ejector 64 that discharges the composite preform 70 determined as a defective product by the inspection unit 60 and a stacking unit 65 that accumulates the composite preform 70 determined as a non-defective product by the inspection unit 60. Are provided sequentially.

Next, a method for producing a composite preform will be described.
As shown in FIG. 1, first, a preform 10a having a mouth part 11a, a body part 20a, a bottom part 30a, and a flange part 17a is supplied in an upright state from a preform supply part 50.

  In this case, the preform body 20A is constituted by the body portion 20a and the bottom portion 30a of the preform 10a.

  Next, the preform 10 a supplied from the preform supply unit 50 is reversed by the reversing unit 51 and sent to the shrinkable tube insertion unit 52.

  In the shrinkable tube insertion portion 52, the preform 10a is in such a posture that the bottom portion 30a faces upward and the mouth portion 11a faces downward.

  Next, the plastic member 40a is inserted from above into the preform 10a at the shrinkable tube insertion portion 52 (see FIG. 4).

In this case, the height of the preform body 20A of the preform 10a, that is, the length from the flange portion 17a to the bottom portion 30a is A, and the height B of the plastic member 40a is equal to or slightly smaller than A. Take a small value. For example, B = A × (0.90-1.00)
It has become.

  In the shrinkable tube insertion portion 52, when the plastic member 40 is completely inserted into the preform 10a, a gap having a length C is formed between the flange portion 17 of the preform 10a and the end portion of the plastic member 40a. Is formed. At this time, the length C of the gap is preferably as small as possible. For example, the length C of the gap is preferably 0 to 1 mm (see FIG. 5). In this way, a composite preform 70 having the preform 10a and the plastic member 40a is obtained. Next, the composite preform 70 is sent to a traveling chain 58 spanned between the wheels 56 and 57 and travels by the traveling chain 58.

  During this time, the plastic member 40a is contracted by the heating portion 53 provided on one side of the traveling chain 58 and is in close contact with the preform 10a.

  Next, the composite preform 70 travels by the travel chain 58, is cooled by the cooling unit 54, and then sent to the inspection unit 60. When the composite preform 70 is cooled during traveling by the traveling chain 58, the cooling unit 54 is not necessarily provided.

  The composite preform 70 sent to the inspection unit 60 rotates at this place, and the composite preform 70 is inspected by the inspection unit 60 during the rotation.

  Specifically, the composite preform 70 is observed from the side by the first imaging unit 61 formed of a camera, and the length C of the gap between the plastic member 40a and the flange portion 17a is inspected by the first imaging unit 61. (See FIG. 2). Then, the inspection signal from the first imaging unit 61 is sent to the control unit 66.

  At the same time, the composite preform 70 is observed from the bottom 30a by the second imaging unit 62 formed of a camera, and the centering inspection of the plastic member 40a and the preform 10a is performed by the second imaging unit 62 (see FIG. 3). The inspection signal from the second imaging unit 62 is sent to the control unit 66. As shown in FIG. 3, the controller 66 determines whether or not the bottom edge 40B of the plastic member 40a is within the allowable range 62a with reference to the outer surface 40A of the plastic member 40a.

  That is, since the outer surface 40a of the plastic member 40 coincides with the outer surface of the preform 10a, the control unit 66 sets the bottom edge 40B of the plastic member 40a within the allowable range 62a with reference to the outer surface 40a of the plastic member 40a. It is determined that the plastic member 40a and the preform 10a are well centered.

  Next, the control unit 66 determines that the length C of the gap between the plastic member 40a and the flange portion 17a is equal to or less than a desired value (1 mm) based on the inspection signal from the first imaging unit 61, and the plastic member 40a and the plastic member 40a. When the centering of the reform 10a is good, it is determined that the composite preform 70 is a good product. The control unit 66 then sends the composite preform 70 determined to be a good product to the stacking unit 65, and discharges the composite preform 70 other than the good product from the ejector 64 as a defective product to the outside.

  As described above, according to the present embodiment, only the composite preform 70 that is accurately formed by inserting the cylindrical plastic member 40a into the correct position with respect to the preform 10a can be collected in the accumulating portion 65. it can.

DESCRIPTION OF SYMBOLS 10 Container main body 10A Composite container 10B Content liquid containing composite container 10a Preform 11a Mouth part 17a Flange part 20a Body part 20A Preform main body 30a Bottom part 40, 40a Plastic member 40A Outer surface 40B Bottom edge 50 Preform supply part 51 Inversion part 52 Contraction tube insertion part 53 Heating part 54 Cooling part 60 Inspection part 61 1st imaging part 62 2nd imaging part 64 Ejector 65 Accumulation part 66 Control part 70 Composite preform

Claims (6)

In composite preform,
A preform having a mouth portion, a preform body, and a flange portion provided between the mouth portion and the preform body;
A cylindrical shrinkable tube inserted into the preform,
The composite preform, wherein the shrinkable tube has a thickness before shrinkage of 0.2 to 0.5 mm. When the height of the preform body is A, the height B of the shrink tube before shrinkage is:
B = A × (0.90-1.00)
The composite preform according to claim 1, wherein   The composite preform according to claim 1 or 2, wherein a gap between the shrinkable tube and the flange portion is 1 mm or less after shrinkage.   A composite container obtained by biaxially stretching blow-molding the composite preform according to claim 1.   A shrinkable tube used for the composite preform according to claim 1.   A preform used for the composite preform according to claim 1.

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