Peeling container, preform, and method and device for manufacturing peeling container

Abstract

The peeling container is provided with a neck part with an opening on one side and a bottomed cylindrical main body part connected with the neck part, and an inner layer is laminated on the inner side of an outer layer. The neck portion of the inner layer has: a first region which is injection-molded in close contact with the inner periphery of the neck portion of the outer layer; a second region which is formed closer to one side than the first region and is injection-molded in a state of protruding from the neck of the outer layer; and a protruding body that is formed on the outer periphery of the second region and that separates the inner layer and the outer layer from one side of the neck when the second region is pressed toward the other side toward the neck of the outer layer.

Description

Technical Field

[0001] The present invention relates to a peeling container, a preform, a method for manufacturing the peeling container, and a manufacturing apparatus. Background Art

[0002] Hitherto, resin containers have been applied to various uses, and resin containers having a plurality of resin layers have also been put to various practical uses. For example, a resin peeling container having a double-layer structure of an inner layer and an outer layer is known, and as the content is discharged, the inner layer peels off from the outer layer. Such a peeling container is also called a gasless bottle and is used, for example, for containers of liquid seasonings such as soy sauce, liquid cosmetics such as makeup lotion, liquid detergents such as shampoo and hand soap, and liquid pharmaceuticals used for disinfection / sterilization.

[0003] In such a peeling container, a lid body having a check valve or the like is attached to the mouth portion of the inner layer, and a vent for introducing external air between the inner layer and the outer layer is provided in the outer layer. Here, a method is known in which a preform of the inner layer and a preform of the outer layer are separately injection-molded, and a preform assembly in which the two are fitted together at normal temperature is reheated and then blow-molded to manufacture a peeling container (for example, Patent Documents 1 to 4, etc.). In the manufacturing methods of Patent Documents 1 to 4, the vent of the peeling container is generally provided in the neck of the peeling container.

[0004] On the other hand, Patent Document 5 proposes a method in which a preform of the outer layer and a preform of the inner layer are continuously formed in one manufacturing apparatus, and a peeling container is manufactured by biaxially stretch blow-molding in a state where heat retained during injection molding is present in the inner layer and the outer layer. In the manufacturing method of the peeling container of Patent Document 5, it is possible to mass-produce a peeling container having excellent appearance aesthetics and physical properties strength in a short manufacturing cycle. For example, in the manufacturing method of Patent Document 5, the vent of the outer layer is provided at the bottom of the peeling container.

[0005] Prior Art Documents Patent Documents Patent Document 1: Japanese Patent No. 628729 Patent Document 2: Japanese Patent No. 6712490 Patent Document 3: Japanese Patent No. 6991674 Patent Document 4: Japanese Unexamined Patent Application Publication No. 2021-172404 Patent Document 5: International Patent Publication No. 2021 / 206082 Summary of the Invention

[0006] Problems to be Solved by the Invention In the above-mentioned Patent Document 5, a recess corresponding to the vent hole is formed at the bottom of the outer layer side of the double-layer preform, and the vent hole is provided at the bottom of the peeled container by blow molding the preform. However, in order to function as the vent hole of the peeled container, it is necessary to suppress the amount of stretching at the bottom of the double-layer preform so that the recess at the bottom of the outer layer does not deform significantly.

[0007] In addition, in the manufacturing method of the above-mentioned Patent Document 5, the inner layer and the outer layer of the double-layer preform are integrally stretched. Therefore, the amount of stretching at the bottom of the preform of the inner layer also becomes small. As a result, the bottom of the inner layer container becomes thick-walled. Therefore, in the manufacturing method of the above-mentioned Patent Document 5, for example, when the inner layer and the outer layer of the peeled container are separated and the materials are reused, there is room for improvement in that it is difficult to pull out the inner layer container from the neck of the outer layer container.

[0008] Therefore, the present invention has been completed in view of such problems, and an object thereof is to provide a peeled container that can cope with mass production in a short manufacturing cycle and can easily distinguish between the inner layer and the outer layer.

[0009] Technical means for solving the problems One aspect of the present invention is a peeled container, which includes a neck that is open on one side and a bottomed cylindrical main body portion connected to the neck, and an inner layer is laminated inside the outer layer. The neck of the inner layer has: a first region that is injection-molded in close contact with the inner circumference of the neck of the outer layer; a second region that is formed at a position closer to one side than the first region and is injection-molded in a state of protruding from the neck of the outer layer; and a protrusion that is formed on the outer circumference of the second region, and when the second region is pressed into the other side toward the neck of the outer layer, the protrusion peels the inner layer and the outer layer from one side of the neck.

[0010] Advantages of the invention According to one aspect of the present invention, it is possible to provide a peeled container that can cope with mass production in a short manufacturing cycle and can easily distinguish between the inner layer and the outer layer. Description of the drawings

[0011] Figure 1 It is a cross-sectional view showing a structural example of the preform of the first embodiment.

[0012] Figure 2 (a) of Figure 1 is a cross-sectional view taken along line A-A of Figure 1 and (b) is a cross-sectional view taken along line B-B of

[0013] Figure 3 It is a cross-sectional view showing a structural example of the peeled container of the first embodiment.

[0014] Figure 4 (a) of Figure 3View of the vicinity of the neck of the stripping container, (b) shows the state where the axial protrusion is pressed into the (a) of Figure 4 View of the state where the axial protrusion is pressed into the (a) of

[0015] Figure 5 is Figure 4 Cross-sectional view taken along line C-C of (b) of

[0016] Figure 6 Schematic view showing the structure of the blow molding apparatus according to the first embodiment.

[0017] Figure 7 View showing a structural example of the first injection molding section.

[0018] Figure 8 View showing the protruding state of the valve pin in the first injection molding section.

[0019] Figure 9 View showing a structural example of the second injection molding section.

[0020] Figure 10 Flow chart showing the steps of the method for manufacturing the container.

[0021] Figure 11 Stereo view showing the shape of the preform and the neck of the stripping container according to the second embodiment.

[0022] Figure 12 In (a) of Figure 12 View of the state where the inner layer is pressed axially into the (a) of DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0024] In the embodiments, for ease of understanding the description, the structures and elements other than the main parts of the present invention are simplified or omitted. Also, in the drawings, the same reference numerals are given to the same elements. It should be noted that the shapes, dimensions, etc. of the respective elements shown in the drawings are schematically shown and do not represent the actual shapes, dimensions, etc.

[0025] <<First Embodiment>> <Structural Example of Preform> First, with reference to Figure 1 , Figure 2 , a structural example of the preform for the stripping container according to the first embodiment will be described. Figure 1 Cross-sectional view showing a structural example of the preform 10 according to the first embodiment. Figure 2 In (a) of Figure 1 Cross-sectional view taken along line A-A ofFigure 2 in (b) is Figure 1 a sectional view taken along line B-B of

[0026] The overall shape of the preform 10 is a bottomed cylindrical shape with an opening at the mouth 13a on one side and closed on the other side. The preform 10 includes: a main body portion 14 formed in a cylindrical shape; a bottom portion 15 closing the other side of the main body portion 14; and a neck portion 13 formed on one side of the main body portion 14 and including the mouth 13a. It should be noted that a thread 13b is formed on the outer peripheral surface of the neck portion 13.

[0027] The preform 10 has a double-layer structure in which an inner layer 12 is laminated inside an outer layer 11. The outer layer 11 and the inner layer 12 are respectively formed of different thermoplastic resin materials by two-stage injection molding as described later. The outer layer 11 is made of a synthetic resin (resin material) having excellent moldability and transparency. On the other hand, the inner layer 12 is made of a synthetic resin (resin material) having properties (such as moisture barrier property, gas barrier property, heat resistance, chemical resistance) capable of stably storing the contents of the container and suppressing deterioration (oxidation). In addition, the resin material of the outer layer 11 is selected to have a higher melting point than the resin material of the inner layer 12.

[0028] Hereinafter, the resin material of the outer layer 11 is also referred to as the first resin material, and the resin material of the inner layer 12 is also referred to as the second resin material.

[0029] The combination of the first resin material and the second resin material can be appropriately selected according to the specifications of the peelable container. As specific types of materials, for example, PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PCTA (polycyclohexane dimethanol terephthalate), Tritan (Tritan (registered trademark): copolyester manufactured by Eastman Chemical Company), PP (polypropylene), PE (polyethylene), PC (polycarbonate), PES (polyethersulfone), PPSU (polyphenylsulfone), PS (polystyrene), COP / COC (cyclic olefin polymer), PMMA (polymethyl methacrylate: acrylic acid), PLA (polylactic acid), etc. can be cited.

[0030] As an example, the first resin material is PET (polyethylene terephthalate), and the second resin material is PP (polypropylene). The melting point of PP is about 160 to 170 °C, and the melting point of PET is higher than that of PP, about 245 to 260 °C.

[0031] In addition, on one side of the preform 10, the inner layer 12 on the inner peripheral side has an axially protruding portion 16 injection-molded to protrude toward one side from the end of the outer layer 11 on the outer peripheral side. Therefore, the axial length of the neck portion in the inner layer 12 is longer than the axial length of the neck portion in the outer layer 11 by an amount corresponding to the axially protruding portion 16. It should be noted that the portion where the neck 13 of the inner layer 12 is injection-molded in close contact with the outer layer is an example of the first region, and the axially protruding portion 16 is an example of the second region.

[0032] In addition, an annular flange 16a extending radially outward is formed at one end of the axially protruding portion 16 of the inner layer 12. In addition, a first rib 17a and a second rib 17b are formed on the outer periphery of the axially protruding portion 16.

[0033] The first rib 17a is an example of a spacer, and is formed on the lower surface of the flange 16a (the other surface of the flange 16a), and extends radially outward of the preform 10. The first rib 17a has a convex shape and protrudes downward from the flat portion of the lower surface of the flange 16a. The first rib 17a is formed in a plurality on the lower surface of the flange 16a, for example, in a radial pattern with respect to the axis center of the preform 10. In Figure 2 FIG. (a) shows an example in which four first ribs 17a are formed on the flange 16a at intervals of 90 degrees. However, the number and arrangement interval of the first ribs 17a are not limited to the above.

[0034] The second rib 17b is an example of a protruding body, and extends axially on the outer periphery of the axially protruding portion 16 at a position on the other side than the lower surface of the flange 16a. The second rib 17b has a convex shape and protrudes outward from the horizontal portion of the outer periphery of the axially protruding portion 16. One or more second ribs 17b are locally formed in the circumferential direction of the axially protruding portion 16, for example, a plurality of second ribs 17b are formed on the outer periphery of the axially protruding portion 16 at intervals in the circumferential direction. It should be noted that two or more second ribs 17b may also be formed at equal intervals on the outer periphery of the axially protruding portion 16. It is particularly preferable to form four or more second ribs 17b at equal intervals on the outer periphery of the axially protruding portion 16.

[0035] The radially protruding amount of the second rib 17b (the height of the second rib 17b from the outer peripheral surface of the axially protruding portion 16) is set to the following dimension: when the flange 16a is pressed toward the other side to press the axially protruding portion 16 into the outer layer 11 as described later, the second rib 17b and the axially protruding portion 16 can be inserted into the inner periphery of the outer layer 11. It should be noted that a rib may also be formed on the other side of the second rib 17b, and the radially protruding amount of the rib is from the other side toward one side (from Figure 1The second rib 17b is an inclined surface that increases from the lower side toward the upper side. In addition, the lower end (the other end) of the second rib 17b is separated from the upper end surface (the one end) of the neck 13 of the outer layer 11. Thus, an outer peripheral surface (annular surface) of the axial protrusion 16 without the second rib 17b is formed between the lower end of the second rib 17b and the upper end surface of the neck 13 of the outer layer 11.

[0036] exist Figure 2 In (a), an example is shown in which two second ribs 17b are formed at an interval of 180 degrees. However, the number and arrangement interval of the second ribs 17b are not limited to the above. In addition, the second rib 17b does not need to be formed at a position overlapping with the first rib 17a, and the first rib 17a and the second rib 17b may also be formed with a phase shift in the circumferential direction. It should be noted that the second rib 17b may also be a shape that extends obliquely from the axial direction.

[0037] In addition, in the area adjacent to the neck 13 in the main body 14 of the preform 10 (hereinafter also referred to as the area below the neck), a protrusion 11a extending in the axial direction is formed on the inner circumference of the outer layer 11. In addition, a groove 12a for receiving the protrusion 11a is formed at a position corresponding to the protrusion 11a on the outer circumference of the inner layer 12. A plurality of protrusions 11a and grooves 12a are formed at predetermined intervals in the circumferential direction of the preform 10. Figure 2 (b) shows an example in which two protrusions 11 a and two grooves 12 a are formed at intervals of 180 degrees. However, the number and arrangement intervals of the protrusions 11 a and the grooves 12 a are not limited to the above.

[0038] In addition, Figure 2 In (a) and (b), an example is shown in which the circumferential position of the second rib 17b coincides with the circumferential position of the protrusion 11a and the groove 12a in the axial direction of the preform 10. However, the circumferential position of the second rib 17b and the circumferential position of the protrusion 11a and the groove 12a may be offset from each other.

[0039] In the bottom portion 15 of the preform 10, an opening 15a is formed at the center of the bottom portion of the outer layer 11 so as to penetrate the outer layer 11. The opening 15a of the outer layer 11 is closed by the inner layer 12 from the inside.

[0040] <Example of the structure of the peelable container> Next, refer to Figure 3 , Figure 4 , Figure 5 , a structural example of the resin peelable container 20 according to the first embodiment will be described. Figure 3 It is a cross-sectional view showing a structural example of the peelable container 20 according to the first embodiment. Figure 4 (a) means Figure 3View near the neck of the peeling container 20 Figure 4 In (b) of Figure 4 Figure showing the state where the axial protrusion 16 is pressed into (a) of Figure 5 Is Figure 4 Cross-sectional view taken along the C-C line of (b) of

[0041] The peeling container 20 is a bottle-shaped resin container obtained by stretch blow molding a preform 10, and contains, for example, a seasoning liquid such as soy sauce. It should be noted that the peeling container 20 can also be used to contain other contents such as a cosmetic liquid for cosmetics.

[0042] Similar to the preform 10, the peeling container 20 has a double-layer structure in which an inner layer 12 is laminated inside an outer layer 11. The peeling container 20 has: a neck 13 having an axial protrusion 16; a cylindrical main body 24; a shoulder 24a connecting one side of the neck 13 and the main body 24; and a bottom 25 closing the other side of the main body 24.

[0043] In the manufacture of the peeling container 20, the main body 14 and the bottom 15 of the preform 10 are expanded by stretch blow molding, so as to form the shoulder 24a, the main body 24, and the bottom 25 of the peeling container 20 respectively. In addition, by stretching the protrusion 11a and the groove 12b of the preform 10, a protrusion 24a1 extending in the axial direction is formed on the inner peripheral side of the outer layer 11 at the shoulder 24a of the peeling container 20, and a groove 24a2 for receiving the protrusion 24a1 is formed on the outer peripheral side of the inner layer 12 (see Figure 4 (a) and (b) of ). The protrusion 24a1 and the groove 24a2 are an example of an anti-offset part.

[0044] On the other hand, the neck 13 of the preform 10 is held by a neck mold 37b described later during blow molding and maintains its shape as it is. Therefore, as Figure 4 Shown in (a) of , the neck 13 and the axial protrusion 16 of the peeling container 20 have the same structure as the neck 13 and the axial protrusion 16 of the above-mentioned preform 10. A lid with a check valve for sealing the inner layer 12 is installed on the neck 13 of the peeling container 20 via a thread 13b (not shown).

[0045] In the peeling container 20 after blow molding, the outer layer 11 and the inner layer 12 of the neck 13 are in a closely attached state. When the lid is installed on the neck 13, as Figure 4As shown in (b), by pressing the flange 16a from the upper side toward the other side using a lid (not shown), the axial protrusion 16 of the inner layer 12 is pressed into the outer layer 11. On the other hand, at the shoulder 24a of the peeling container 20, the protrusion 24a1 of the outer layer 11 contacts the groove portion 24a2 of the inner layer 12, generating a reaction force against the force pressing the flange 16a.

[0046] Thus, if the axial protrusion 16 of the inner layer 12 is pressed into the other side relative to the outer layer 11 of the neck 13 with a force equal to or greater than a certain value, the second rib 17b is inserted into the inside of the outer layer 11 together with the axial protrusion 16. At this time, as Figure 5 shown, the second rib 17b contacts the inner circumference of the outer layer 11, so that the axial protrusion 16 is pressed toward the inner diameter side and slightly narrowed, and is displaced in an oval or substantially polygonal cross-section. Thus, at the neck 13 of the peeling container 20, the outer layer 11 and the inner layer 12 are peeled off from one side. In addition, by the second rib 17b contacting the inner circumferential surface of the outer layer 11, a gap is ensured between the outer layer 11 and the inner layer 12. In addition, by rotating the lid engaged with the thread 13b of the outer layer 11 to lower the lid, when pressing the flange 16a from the upper side toward the other side using the lid, the positional deviation (relative rotation) between the outer layer 11 and the inner layer 12 can be suppressed.

[0047] If the axial protrusion 16 is further pressed from the above state, the peeling between the outer layer 11 and the inner layer 12 further expands downward. As Figure 4 shown in (b), if the peeling between the outer layer 11 and the inner layer 12 proceeds to the vicinity of the shoulder 24a of the peeling container 20, the inner layer 12 bends inward at the boundary between the neck 13 and the shoulder 24a, and the groove portion 24a2 of the inner layer 12 contacts the protrusion 24a1 of the shoulder 24a, thus completing the peeling.

[0048] In addition, in the state where the axial protrusion 16 is pressed in, the first rib 17a is sandwiched between the flange 16a and one end of the outer layer 11. Therefore, at one end of the outer layer 11, the first rib 17a serves as a spacer from the flange 16a, thereby forming a ventilation path communicating with the above gap. As described above, in the first embodiment, by pressing the flange 16a into the other side, a ventilation path for introducing external air between the outer layer 11 and the inner layer 12 can be formed at the neck 13 of the peeling container 20.

[0049] In the peeling container 20, the content is filled in the space inside the inner layer 12. In the peeling container 20, when the content is discharged from the inner layer 12, air gradually flows into the space between the outer layer 11 and the inner layer 12 from the ventilation path, and the outer layer 11 and the inner layer 12 are peeled off. Thus, the volume occupied by the content in the container can be replaced with air without the content in the inner layer 12 contacting the air, and the content filled in the inner layer 12 can be discharged out of the container.

[0050] It should be noted that at the center of the bottom 25 of the peeling container 20, similarly to the preform 10, an opening 25a (non-laminated part, single-layer part) penetrating the outer layer 11 is formed. In the opening 25a, the material of the inner layer 12 is filled in a manner to block the opening 25a. Near the opening 25a of the bottom 25 of the peeling container 20, the inner layer 12 is in a state of being exposed outside the outer layer 11. At the opening 25a of the peeling container 20, the inner layer 12 is exposed to the outside, so that the inner layer 12 is partially fixed to the outer layer 11, suppressing the positional deviation of the inner layer 12 relative to the outer layer 11.

[0051] <Description of the manufacturing apparatus of the peeling container> Figure 6 It is a diagram schematically showing the structure of the blow molding apparatus 30 of the first embodiment. The blow molding apparatus 30 of the first embodiment is an example of the manufacturing apparatus of the peeling container 20, and adopts a hot preform method (also called a one-step method) in which the preform 10 is not cooled to room temperature and the retained heat (internal heat) during injection molding is effectively utilized to blow-mold the peeling container 20.

[0052] The blow molding apparatus 30 includes a first injection molding section 31, a first temperature adjustment section 32, a second injection molding section 33, a second temperature adjustment section 34, a blow molding section 35, a take-out section 36, and a conveying mechanism 37. The first injection molding section 31, the first temperature adjustment section 32, the second injection molding section 33, the second temperature adjustment section 34, the blow molding section 35, and the take-out section 36 are arranged at positions that rotate the same specified angle (for example, 60 degrees) each time around the conveying mechanism 37. It should be noted that the blow molding apparatus 30 may also be configured to omit the first temperature adjustment section 32. In this case, each molding station is arranged at a position that rotates 72 degrees each time around the conveying mechanism 37.

[0053] In addition, in the first injection molding section 31 and the second injection molding section 33, a core mold lifting mechanism (not shown) is provided above the conveying mechanism 37.

[0054] (Conveying mechanism 37) The conveying mechanism 37 includes a transfer plate 37a that rotates around an axis perpendicular to the plane of the paper of Figure 6 . On the transfer plate 37a, a neck mold 37b (not shown in Figure 6 ) that holds the neck 13 of the preform 10 (or the peeling container 20) is arranged at least one at each specified angle.

[0055] The neck mold 37b defines the shape of the neck 13 of the outer layer 11 in the first injection molding section 31. Further, the neck mold 37b defines the outer peripheral shape of the axially protruding portion 16 of the inner layer 12, the outer peripheral surface and the lower surface of the flange 16a, and the shapes of the first rib 17a and the second rib 17b in the second injection molding section 33, respectively.

[0056] The conveying mechanism 37 conveys the preform 10 (or the peeling container 20) held by the neck mold 37b in the order of the first injection molding section 31, the first temperature adjusting section 32, the second injection molding section 33, the second temperature adjusting section 34, the blow molding section 35, and the take-out section 36 by moving the position of the transfer plate 37a in the rotational direction. It should be noted that the conveying mechanism 37 can also raise and lower the transfer plate 37a, and also performs the operations related to mold closing and mold opening (demolding) in the first injection molding section 31 and the second injection molding section 33.

[0057] (First injection molding section 31) The first injection molding section 31 includes a cavity mold 40 and a core mold 41, and cooperates with the neck mold 37b conveyed during molding to manufacture the outer layer 11 of the preform 10. A first injection device 38 that supplies a first resin material via a hot runner mold (not shown) is connected to the first injection molding section 31. The cavity mold 40 is fixed to the machine base of the blow molding device 30, and the core mold 41 is fixed to the core mold lifting mechanism.

[0058] Figure 7 , Figure 8 FIG. is a view showing the first injection molding section 31 for molding the outer layer 11 of the preform 10.

[0059] The cavity mold 40 is a mold that defines the outer peripheral shape of the outer layer 11. A resin supply portion 42 for introducing the first resin material plasticized (melted) by the first injection device 38 into the cavity mold 40 is connected to the bottom of the cavity mold 40.

[0060] The core mold 41 is a mold that defines the shape of the inner peripheral side of the outer layer 11 and is inserted into the inner periphery of the cavity mold 40 from above. In the region of the core mold 41 corresponding to the lower part of the neck of the outer layer 11, a groove 41a corresponding to the protrusion 11a of the outer layer 11 is formed along the axial direction.

[0061] Further, a valve pin 43 that can move axially to a position close to the core mold 41 is provided in the resin supply portion 42. The valve pin 43 is a rod-shaped member that opens and closes the resin supply portion 42 and is housed inside in such a manner that it does not protrude from the resin supply portion 42 before the first resin material is filled into the mold space. After the first resin material is filled into the mold space, as Figure 8 shown, the valve pin 43 protrudes to a position close to the core mold 41. By the movement of the valve pin 43 during such injection molding, a thin film portion 11b having a wall thickness thinner than that of the peripheral portion can be formed at the center of the bottom of the outer layer 11.

[0062] As Figure 7 , Figure 8 shown, in the first injection molding section 31, the cavity mold 40, the core mold 41 and the neck mold 37b of the conveying mechanism 37 are closed to form a mold space for the outer layer 11. Then, by injecting the first resin material from the bottom of the mold space via the resin supply section 42, the outer layer 11 of the preform 10 is manufactured in the first injection molding section 31.

[0063] In addition, when the first injection molding section 31 is opened, the neck mold 37b of the conveying mechanism 37 is not opened and the outer layer 11 of the preform 10 is held and conveyed as it is. The number of preforms 10 simultaneously molded by the first injection molding section 31 (i.e., the number of peeling containers 20 that can be simultaneously molded by the blow molding device 30) can be appropriately set.

[0064] (First temperature adjustment section 32) The first temperature adjustment section 32 includes a temperature adjustment mold (not shown) (a heating tank or temperature adjustment tank for externally adjusting the temperature of the outer layer 11, and a heating rod or temperature adjustment rod (or air introduction rod) for internally adjusting the temperature of the outer layer 11). The first temperature adjustment section 32 cools (or heats) the outer layer 11 in a high-temperature state after injection molding by accommodating it in the temperature adjustment mold maintained at a specified temperature. In addition, the first temperature adjustment section 32 also has the function of adjusting the temperature distribution of the outer layer 11 to a specified state before conveying it to the second injection molding section 33.

[0065] (Second injection molding section 33) The second injection molding section 33 includes a cavity mold 50, a core mold 51, and cooperates with the neck mold 37b conveyed during molding to injection mold the inner layer 12 on the inner peripheral side of the outer layer 11. A second injection device 39 for supplying the second resin material via a hot runner mold (not shown) is connected to the second injection molding section 33. The cavity mold 50 is fixed to the machine base of the blow molding device 30, and the core mold 51 is fixed to the core mold lifting mechanism.

[0066] Figure 9 It is a view showing the second injection molding section 33 for molding the inner layer 12 of the preform 10.

[0067] The cavity mold 50 is a mold for accommodating the outer layer 11. A resin supply section 52 for introducing the second resin material plasticized (melted) by the second injection device 39 is connected to the bottom of the cavity mold 50. The core mold 51 is a mold for defining the shape of the inner peripheral side of the inner layer 12 and the axial protrusion 16 and the shape of the upper surface of the flange 16a, and is inserted into the inner periphery of the cavity mold 50 from above.

[0068] As Figure 9As shown, the second injection molding section 33 houses the outer layer 11 of the preform 10 injection molded by the first injection molding section 31. In a state where the second injection molding section 33 is closed, a mold space is formed between the inner circumference of the outer layer 11, the neck mold 37b, and the surface of the core mold 51. Then, by injecting a second resin material from the bottom of the above-mentioned mold space via the resin supply section 52, the inner layer 12 is laminated on the inner circumferential side of the outer layer 11 in the second injection molding section 33, and the preform 10 having the axial protrusion 16 is manufactured.

[0069] In addition, in a state where the second injection molding section 33 is closed, a molding space (cavity) corresponding to the first rib 17a and a molding space (not shown) corresponding to the second rib 17b are formed in the mold. In addition, between the molding spaces of the lower end (the other end) of the second rib 17b and the upper end surface (one end) of the neck 13 of the outer layer 11, the convex portion on the inner circumferential surface of the neck mold 37b of the neck 13 of the inner layer 12 is closest to the outer circumferential surface of the core mold 51, and a molding space corresponding to the outer circumferential surface (annular surface) of the axial protrusion 16 without the second rib 17b is formed.

[0070] (Second temperature adjustment section 34) The second temperature adjustment section 34 includes a temperature adjustment mold (not shown) (a heating tank or temperature adjustment tank for externally adjusting the temperature of the preform 10, and a heating rod or temperature adjustment rod (or air introduction rod) for internally adjusting the temperature of the preform 10). The second temperature adjustment section 34 equalizes the temperature and removes temperature deviation by housing the preform 10 conveyed from the second injection molding section 33 in a mold unit maintained at a specified temperature, and adjusts the temperature of the preform 10 to a temperature suitable for final blow molding (for example, about 90°C to 105°C). In addition, the second temperature adjustment section 34 also has the function of cooling the preform 10 in a high-temperature state after injection molding.

[0071] (Blow molding section 35) The blow molding section 35 blow molds the preform 10 whose temperature has been adjusted by the second temperature adjustment section 34 to manufacture the peelable container 20.

[0072] The blow molding section 35 includes a pair of split molds corresponding to the shape of the peelable container 20, namely a blow cavity mold, a bottom mold, a stretching rod, and an air introduction member (all not shown). The blow molding section 35 blow molds while stretching the preform 10. Thus, the preform 10 can be shaped into the shape of the blow cavity mold to manufacture the peelable container 20.

[0073] (Take-out section 36) The take-out part 36 is configured to release the neck 13 and the axially protruding part 16 of the peeled container 20 manufactured by the blow molding part 35 from the neck mold 37b, and take out the peeled container 20 to the outside of the blow molding device 30.

[0074] <Explanation of the method for manufacturing a container> Next, a method for manufacturing the peeled container 20 of the blow molding device 30 according to the first embodiment will be described. Figure 10 It is a flowchart showing the steps of the method for manufacturing the peeled container 20.

[0075] (Step S101: First injection molding process) First, as Figure 7 shown, in the first injection molding part 31, the first resin material is injected from the first injection device 38 into the mold space formed by the cavity mold 40, the core mold 41, and the neck mold 37b to manufacture the outer layer 11 of the preform 10. At this time, using the groove of the core mold 41, a protrusion 11a is formed on the inner periphery of the outer layer 11 in the area below the neck.

[0076] In addition, in the first injection molding part 31, as Figure 8 shown, after the outer layer 11 of the preform 10 is molded, a process of protruding the valve pin 43 to a position close to the core mold 41 is performed. Thereby, a thin film part 11b having a wall thickness thinner than the peripheral part is formed at the center of the bottom of the outer layer 11.

[0077] After that, the mold of the first injection molding part 31 is opened, and the outer layer 11 is demolded. When the mold of the first injection molding part 31 is opened, the transfer plate 37a of the transfer mechanism 37 moves a corresponding amount by a specified angle in the rotational direction. Thereby, the outer layer 11 of the preform 10 held by the neck mold 37b is conveyed to the first temperature adjustment part 32 in a state including the retained heat during injection molding.

[0078] (Step S102: First temperature adjustment process) Next, in the first temperature adjustment part 32, the outer layer 11 of the preform 10 is housed in the temperature adjustment mold, and the cooling of the outer layer 11 and the adjustment of the temperature distribution (equalization, removal of temperature deviation) are performed. It should be noted that the first temperature adjustment process may be omitted.

[0079] After the first temperature adjustment process (or the first injection molding process), the transfer plate 37a of the transfer mechanism 37 moves a corresponding amount by a specified angle in the rotational direction. Thereby, the temperature-adjusted outer layer 11 held by the neck mold 37b is conveyed to the second injection molding part 33.

[0080] (Step S103: Second injection molding process) Next, the outer layer 11 of the preform 10 is received in the second injection molding section 33, and the inner layer 12 is injection molded.

[0081] In the second injection molding section 33, as Figure 9 shown, a mold space is formed between the inner periphery of the outer layer 11, the neck mold 37b, and the surface of the core mold 51 facing them, and the second resin material is injected into the mold space from the second injection device 39. It should be noted that a film portion 11b is formed at the bottom of the outer layer 11, but the film portion 11b breaks due to the injection pressure of the second resin material, and an opening portion 15a is formed at the bottom. The second resin material is guided to the inner peripheral side of the outer layer 11 from the opening portion 15a.

[0082] In the second injection molding section 33, the axially protruding portion 16 and the flange 16a of the inner layer 12 are integrally formed by using the neck mold 37b and the core mold 51. In addition, the first rib 17a and the second rib 17b are integrally formed on the outer periphery of the axially protruding portion 16 by using the neck mold 37b. In addition, in the second injection molding section 33, by using the protruding portion 11a of the outer layer 11, a groove portion 12a for receiving the protruding portion 11a is formed in the area below the neck on the outer periphery of the inner layer 12. In addition, the lower end (the other end) of the second rib 17b is separated from the upper end surface (one end) of the neck portion 13 of the outer layer 11. Thus, a circumferential surface (annular surface) of the outer periphery of the axially protruding portion 16 without the second rib 17b is formed between the lower end of the second rib 17b and the upper end surface of the neck portion 13 of the outer layer 11.

[0083] Here, the temperature of the second resin material filled in the second injection molding section 33 is set to a temperature lower than the melting point of the first resin material. In addition, the surface temperature of the outer layer 11 when the second resin material is filled in the second injection molding section 33 is cooled to a temperature below the melting point of the second resin material.

[0084] In the second injection molding section 33, the cavity mold 50 faces the outer peripheral side of the outer layer 11, and the shape of the outer layer 11 is maintained from the outer peripheral side by the cavity mold 50. Therefore, in the second injection molding section 33, even if the second resin material contacts the outer layer 11, thermal deformation of the outer layer 11 can be suppressed.

[0085] As described above, by using the first injection molding process and the second injection molding process, the inner layer 12 is laminated on the inner peripheral side of the outer layer 11, and the preform 10 having the axially protruding portion 16 is manufactured.

[0086] After that, the mold of the second injection molding section 33 is opened, and the preform 10 is demolded. When the mold of the second injection molding section 33 is opened, the transfer plate 37a of the transfer mechanism 37 moves a corresponding amount by a predetermined angle in the rotation direction. Thus, the preform 10 held by the neck mold 37b is conveyed to the second temperature adjustment section 34 in a state including the heat retained during injection molding.

[0087] (Step S104: Second Temperature Adjustment Process) Next, in the second temperature adjustment unit 34, the preform 10 is housed in a mold unit for temperature adjustment, and temperature adjustment is performed to bring the temperature of the preform 10 close to the temperature suitable for final blow molding. After that, the transfer plate 37a of the transfer mechanism 37 moves a corresponding amount by a specified angle in the rotational direction. Thereby, the temperature-adjusted preform 10 held by the neck mold 37b is transported to the blow molding section 35.

[0088] (Step S105: Blow Molding Process) Next, in the blow molding section 35, blow molding of the peeling container 20 is performed.

[0089] First, the blow molding cavity mold is closed to house the preform 10 in the mold space. By lowering the air introduction member (blow molding core), the air introduction part is brought into contact with the neck 13 of the preform 10. Then, the stretching rod is lowered to press the bottom 15 of the preform 10 from the inner surface, longitudinal axis stretching is performed as needed, and blow molding air is supplied from the air introduction member, thereby performing transverse axis stretching on the preform 10. Thereby, the preform 10 bulges in a manner that closely adheres to the mold space of the blow molding cavity mold and is shaped, and is blow molded into the peeling container 20.

[0090] (Step S106: Container Removal Process) When the blow molding is completed, the blow molding cavity mold is opened. Thereby, the peeling container 20 can be moved from the blow molding section 35.

[0091] Next, the transfer plate 37a of the transfer mechanism 37 moves a corresponding amount by a specified angle in the rotational direction, and the peeling container 20 is transported to the removal section 36. In the removal section 36, the neck 13 and the axially protruding portion 16 of the peeling container 20 are released from the neck mold 37b, and the peeling container 20 is taken out to the outside of the blow molding apparatus 30.

[0092] Thus, one cycle in the manufacturing method of the peeling container ends. After that, the transfer plate 37a of the transfer mechanism 37 moves a corresponding amount by a specified angle in the rotational direction, and the above-described processes of S101 to S106 are repeated. It should be noted that when the blow molding apparatus 30 is operating, six sets of manufacturing of the peeling containers 20 with a time difference of one process each are executed in parallel.

[0093] In addition, in terms of the structure of the blow molding apparatus 30, the standby times of the first injection molding process, the first temperature adjustment process, the second injection molding process, the second temperature adjustment process, the blow molding process, and the container removal process are respectively of the same length. Similarly, the transfer times between the respective processes are also respectively of the same length.

[0094] Next, the effects of the first embodiment will be described.

[0095] In the first embodiment, the outer layer 11 of the preform 10 is formed in the first injection molding process, and the inner layer 12 is injection molded inside the outer layer 11 from the opening 15a of the outer layer 11 in the second injection molding process to manufacture the double-layer preform 10. According to the first embodiment, the inner layer can be continuously injection molded while the outer layer retains heat during injection molding, and a double-layer preform 10 suitable for the specifications of the peelable container 20 can be manufactured. In the first embodiment, since the double-layer preform 10 is demolded while both the outer layer and the inner layer retain heat during injection molding, a suitable preform 10 can be obtained when manufacturing the peelable container 20 by the hot preform blow molding method.

[0096] Furthermore, in the first embodiment, the double-layer preform 10 is stretch blow molded while retaining heat during injection molding to manufacture the peelable container 20. Therefore, in the first embodiment, the peelable container 20 with excellent appearance aesthetics and physical properties can be manufactured by the hot preform blow molding method. Compared with the cold preform blow molding, in the first embodiment, it is not necessary to cool the manufactured preform 10 to near room temperature, nor is a reheating process of the preform 10 required. Thus, according to the first embodiment, a series of processes from the injection molding of the preform 10 to the blow molding of the peelable container 20 can be completed in a relatively short time. That is, in the first embodiment, compared with the cold preform method that requires separately manufacturing two preforms, the peelable container 20 can be mass-produced from the resin material with a shorter manufacturing cycle (manufacturing time).

[0097] In addition, in the peelable container 20 of the first embodiment, an axial protrusion 16 where the inner layer protrudes outward more than the outer layer is formed at the neck 13. And in the peelable container 20 of the first embodiment, by pressing the axial protrusion 16 when installing the lid, a gap is formed between the outer layer and the inner layer at the neck 13, enabling external air to flow into the space between the outer layer and the inner layer from the neck 13 side.

[0098] Thereby, in the peelable container 20 of the first embodiment, compared with the case where a vent hole is formed at the bottom 15, the draw ratio of the bottom 15 can be increased, and the bottom 15 can be thinned. By thinning the bottom 15, it is easier to pull out the inner container from the neck 13 of the outer layer, and the distinction between the inner layer and the outer layer becomes easier during reuse. It should be noted that in the first embodiment, since the draw ratio of the bottom can be increased, the restriction on the wall thickness distribution of the preform 10 is also alleviated.

[0099] Further, in the first embodiment, by providing the second rib 17b on the outer periphery of the axial protrusion 16, the second rib 17b expands the gap when the axial protrusion 16 is pressed in, and the gap between the outer layer and the inner layer of the neck 13 is maintained by the second rib 17b. Thereby, when the axial protrusion 16 is pressed in, a gap can be reliably formed between the outer layer and the inner layer of the neck 13.

[0100] Further, in the first embodiment, a flange 16a is formed on the axial protrusion 16, and the first rib 17a is provided on the lower surface of the flange 16a. Thereby, when the axial protrusion 16 is pressed in, by sandwiching the first rib 17a between the end of the outer layer and the flange 16a, a ventilation path communicating with the gap of the neck 13 can be ensured between the end of the outer layer and the flange 16a.

[0101] It should be noted that in the structure of the first embodiment, the ventilation path is formed by pressing the axial protrusion 16 after blow molding, so vents do not need to be provided in the preform 10 during injection molding. Therefore, there is no need to add a movable mold for forming vents in the injection molding die, and thus the manufacturing cost of the peeling container 20 can be suppressed.

[0102] <<Second Embodiment>> Figure 11 It is a perspective view showing the shapes of the preform 10 and the neck of the peeling container 20 of the second embodiment. Figure 12 (a) is a cross-sectional view showing the vicinity of the neck of the peeling container 20, Figure 12 (b) is a view showing the state in which the inner layer is pressed in the axial direction from Figure 12 (a). It should be noted that the second embodiment is a modification of the first embodiment, and the same reference numerals are given to the same structures as those in the first embodiment and repeated descriptions are omitted. The manufacturing method and manufacturing apparatus of the second embodiment are the same as those of the first embodiment. In the second embodiment, the structure of the axial protrusion 16 of the inner layer 12 in the preform or the peeling container, and the structure of the die forming this part are different from those of the first embodiment.

[0103] The preform 10 and the neck 13 of the peeling container 20 of the second embodiment have an axial protrusion 16 in which the inner layer 12 on the inner peripheral side protrudes more to one side than the end of the outer layer 11 on the outer peripheral side. Therefore, the axial length of the neck in the inner layer 12 is longer than the axial length of the neck of the outer layer 11 by an amount corresponding to the axial protrusion 16. It should be noted that the part where the inner layer 12 of the neck 13 is injection-molded in close contact with the outer layer is an example of the first region, and the axial protrusion 16 is an example of the second region.

[0104] The axially protruding portion 16 in the second embodiment has an annular flange 16a1 extending radially outward at one end thereof. The flange 16a1 forms an annular step extending circumferentially on one side of the inner layer 12 and is thicker than other portions of the inner layer 12 .

[0105] In addition, a notch 16b is formed on the other side surface (lower surface) of the flange 16a1, which is recessed toward one side (upper side in the figure). One or more notches 16b are formed locally in the circumferential direction of the flange 16a1, preferably two or more notches 16b are formed, and are formed to extend in the radial direction of the flange 16a1. In the case where two or more notches 16b are formed, it is preferred that a plurality of notches 16b are arranged at equal intervals on the other side surface (lower surface) of the flange 16a1. In the case where two notches 16b are provided, for example, two notches 16b may be arranged on the other side surface (lower surface) of the flange 16a1 located at an opposing position with respect to the center of the mouth 13a.

[0106] In addition, a rib 17c is formed on the outer periphery of the axial protrusion 16 on the other side of the flange 16a1. The rib 17c is an example of a protruding body, and extends in the axial direction at a position on the outer periphery of the axial protrusion 16 closer to the other side than the lower surface of the flange 16a1. One or more ribs 17c are formed locally in the circumferential direction of the axial protrusion 16, for example, a plurality of ribs 17c are formed on the outer periphery of the axial protrusion 16 at a certain interval in the circumferential direction. Two or more ribs 17c may be formed at equal intervals on the outer periphery of the axial protrusion 16. It is particularly preferred that four or more ribs 17c are formed at equal intervals on the outer periphery of the axial protrusion 16. In addition, the lower end (end on the other side) of the rib 17c is separated from the upper end surface (end on one side) of the neck 13 of the outer layer 11. As a result, the outer peripheral surface (annular surface) of the axial protrusion 16 without the rib 17c is formed between the lower end of the rib 17c and the upper end surface of the neck 13 of the outer layer 11.

[0107] It should be noted that the radial protrusion of the rib may be formed on the other side (lower end side) of the rib 17c from the other side toward the one side (from the Figure 1 The rib 17c may be formed to have an inclined surface or curved surface that increases from the lower side toward the upper side. In addition, the circumferential width (diameter) of the rib 17c may also be formed to increase from the other side toward the one side (from the Figure 1 The rib 17c may also be shaped so as to extend obliquely from the axial direction.

[0108] In addition, the circumferential position of one or more ribs 17c is arranged to overlap with the circumferential position of the cutout 16b. In addition, when there are a plurality of cutouts 16b, it is preferred that the ribs 17c having the same number as the cutouts 16b are arranged to overlap each other in the circumferential position. It should be noted that it is not necessary for all ribs 17c to be formed at positions overlapping with the cutouts 16c.

[0109] likeFigure 12 As shown in (a) of FIG. , in the peeled container 20 after blow molding, the outer layer 11 and the inner layer 12 of the neck 13 are in close contact with each other. Further, a check valve-equipped cap (not shown) for sealing the inner layer 12 is attached to the neck 13 of the peeled container 20 via the thread 13b of the outer layer 11.

[0110] When attaching the cap to the neck 13, the cap is screwed onto the thread 13b of the outer layer 11. Thus, as Figure 12 shown in (b) of FIG. , the axial protrusion 16 of the inner layer 12 is pressed into the outer layer 11 by a cap (not shown) pressing the flange 16a1 from above toward the other side. It should be noted that the pressing-in of the axial protrusion 16 is performed until the other side surface (lower surface) of the flange 16a1 reaches the position where it abuts against the end surface (top surface) of the outer layer 11.

[0111] On the other hand, since the inner layer 12 of the peeled container 20 is filled with the content, the inner layer 12 that receives the internal pressure of the content expands outward. Thus, at the shoulder 24a of the peeled container 20, the inner layer 12 abuts against the outer layer 11 by the internal pressure of the content, and a reaction force is generated against the force pressing the flange 16a1. It should be noted that in the second embodiment, similarly to the first embodiment, the protrusion 24a1 of the outer layer 11 and the groove 24a2 of the inner layer 12 can be formed at the shoulder 24 of the peeled container 20.

[0112] In the peeled container 20 of the second embodiment, when the axial protrusion 16 of the inner layer 12 is pressed into the other side with respect to the outer layer 11 of the neck 13 with a force equal to or greater than a certain level, the rib 17c is inserted into the inside of the outer layer 11 together with the axial protrusion 16. At this time, similarly to the first embodiment, the rib 17c comes into contact with the inner circumference of the outer layer 11, so that the axial protrusion 16 is pressed toward the inner diameter side and slightly narrowed, and is displaced in an elliptical cross-section. Thus, at the neck 13 of the peeled container 20, the outer layer 11 and the inner layer 12 are peeled off from one side. If the axial protrusion 16 is further pressed in from the above state, the peeling of the outer layer 11 and the inner layer 12 further expands downward (near the shoulder 24a of the peeled container 20), and the inner layer 12 flexes inward at the boundary between the neck 13 and the shoulder 24a, thereby completing the peeling.

[0113] On the other hand, if the axial protrusion 16 is pressed axially, the surface (lower surface) on the other side of the flange 16a1 abuts against the surface (upper end surface, top surface) on one side of the outer layer 11. At this time, at the position of the notch 16b of the flange 16a1, a gap extending in the radial direction is formed between the flange 16a1 and the outer layer 11. The gap formed by the notch 16b communicates with the gap generated by the peeling of the above-mentioned outer layer 11 and inner layer 12 to form a ventilation path. As described above, in the second embodiment, by pressing the flange 16a1 to the other side, a ventilation path for introducing external air between the outer layer 11 and the inner layer 12 can be formed in the neck 13 of the peeling container 20.

[0114] It should be noted that, in the second embodiment, the rigidity of the annular flange 16a1 is higher than that of other parts of the inner layer 12, and the flange 16a1 is difficult to deform. Therefore, the flange 16a1 is pressed approximately evenly over the circumference, and the axial protrusion 16 easily descends straight down. Therefore, in the neck 13, the inner layer 12 and the outer layer 13 are more likely to be peeled off more reliably.

[0115] The present invention is not limited to the above-described embodiments, and various improvements and design changes can be made without departing from the gist of the present invention.

[0116] In the above embodiment, an example in which the protrusion 11a is formed on the inner peripheral side of the outer layer 11 and the groove 12a is formed on the outer peripheral side of the inner layer 12 in the region under the neck of the preform 10 has been described. However, the relationship between the groove and the protrusion of the two can be reversed, and a groove can be formed on the inner peripheral side of the outer layer 11 and a protrusion can be formed on the outer peripheral side of the inner layer 12 in the region under the neck of the preform 10.

[0117] In addition, the embodiments disclosed this time are illustrative in all respects and should not be considered restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include the meaning equivalent to the claims and all changes within the scope.

[0118] Reference Numeral Explanation 10... preform, 11... outer layer, 12... inner layer, 13... neck, 14... body part, 15... bottom, 16... axial protrusion, 16a, 16a1... flange, 16b... notch, 17a... first rib, 17b... second rib, 17c... rib, 20... peeling container, 24... body part, 24a... shoulder, 24a1... protrusion, 24a2... groove, 25... bottom, 30... blow molding device, 31... first injection molding part, 32... first temperature adjustment part, 33... second injection molding part, 34... second temperature adjustment part, 35... blow molding part.

Claims

1. A peeling container includes a neck with an opening on one side and a bottomed cylindrical main body connected to the neck. An inner layer is laminated inside the outer layer of the peeling container. Among them, the neck of the inner layer has: a first region that is injection-molded in close contact with the inner circumference of the neck of the outer layer; a second region that is formed at a position closer to the one side than the first region and is injection-molded in a state of protruding from the neck of the outer layer; and a protrusion formed on the outer circumference of the second region. When the second region is pressed into the neck of the outer layer toward the other side, the protrusion peels the inner layer and the outer layer from one side of the neck.

2. The peeling container according to claim 1, wherein when the protrusion is pressed into the neck of the outer layer toward the other side, the protrusion contacts the inner surface of the outer layer, causing the inner layer to displace away from the outer layer and maintaining a gap between the outer layer and the inner layer.

3. The peeling container according to claim 2, wherein the neck of the inner layer further has: a flange formed on one side of the second region and extending radially outward; and a spacer formed on the surface on the other side of the flange and locally arranged in the circumferential direction of the second region. When the second region is pressed into the neck of the outer layer, the spacer abuts against one end of the outer layer, maintaining a ventilation path communicating with the gap between the flange and the outer layer.

4. The peeling container according to claim 2, wherein the neck of the inner layer further has a flange formed on one side of the second region and extending radially outward. On the surface on the other side of the flange, a notch is formed that is recessed toward one side of the flange and extends in the radial direction of the flange. When the second region is pressed into the neck of the outer layer, the flange abuts against one end of the outer layer, and a ventilation path communicating with the gap is formed between the flange and the outer layer through the notch.

5. The peeling container according to any one of claims 1 to 4, wherein the peeling container further includes a shoulder connecting the neck and the main body, the shoulder has an anti-offset portion that receives the inner layer moving toward the other side when the second region is pressed into the neck of the outer layer.

6. The peeling container according to claim 5, wherein the anti-offset portion is composed of the following components: a protrusion formed on the inner circumference of the outer layer and extending axially; and a groove formed on the outer circumference of the inner layer and extending axially.

7. A preform for forming a peeling container. The peeling container includes a neck with an opening on one side and a bottomed cylindrical main body connected to the neck, and an inner layer is laminated inside the outer layer. Among them, the neck of the inner layer has: a first region that is injection-molded in close contact with the inner circumference of the neck of the outer layer; a second region that is formed at a position closer to the one side than the first region and is injection-molded in a state of protruding from the neck of the outer layer; and A protrusion is formed on the outer periphery of the second region. When the second region is pressed into the other side by the neck portion facing the outer layer, the protrusion separates the inner layer and the outer layer from one side of the neck portion.

8. A method for manufacturing a peeling container, the peeling container including a neck portion with an opening on one side and a bottomed cylindrical main body portion connected to the neck portion, wherein, the manufacturing method includes: A first injection molding process of injection molding the outer layer of a bottomed cylindrical preform using a first resin material; A second injection molding process of injecting a second resin material different from the first resin material and laminating the inner layer on the inner side of the outer layer; and A blow molding process of blow molding the preform obtained in the second injection molding process in a state of retaining heat during injection molding to manufacture the peeling container, the neck portion of the inner layer includes: A first region that is injection molded in close contact with the inner periphery of the neck portion of the outer layer; A second region that is formed at a position closer to the one side than the first region and is injection molded in a state of protruding from the neck portion of the outer layer; and A protrusion is formed on the outer periphery of the second region. When the second region is pressed into the other side by the neck portion facing the outer layer, the protrusion separates the inner layer and the outer layer from one side of the neck portion.

9. A manufacturing apparatus for a peeling container, the peeling container including a neck portion with an opening on one side and a bottomed cylindrical main body portion connected to the neck portion, wherein, the manufacturing apparatus includes: A first injection molding section that injection molds the outer layer of a bottomed cylindrical preform using a first resin material; A second injection molding section that injects a second resin material different from the first resin material and laminates the inner layer on the inner side of the outer layer; and A blow molding section that blow molds the preform obtained by the second injection molding section in a state of retaining heat during injection molding to manufacture the peeling container, the neck portion of the inner layer includes: A first region that is injection molded in close contact with the inner periphery of the neck portion of the outer layer; A second region that is formed at a position closer to the one side than the first region and is injection molded in a state of protruding from the neck portion of the outer layer; and A protrusion is formed on the outer periphery of the second region. When the second region is pressed into the other side by the neck portion facing the outer layer, the protrusion separates the inner layer and the outer layer from one side of the neck portion.

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