Peeling container and method for manufacturing the peeling container

Abstract

The peeling container of the present invention has: an outer layer formed of a first resin material; and a bag-shaped inner layer provided on the inner peripheral side of the outer layer, formed of a second resin material different from the first resin material, and holes for introducing air between the outer layer and the inner layer are provided in the outer layer. The peeling container includes: a neck having an opening communicating with the inside of the inner layer; a shoulder continuous from the neck and extending radially; a bottomed cylindrical body portion; and a reduced diameter portion connecting the shoulder and the body portion. The diameter of the outer peripheral edge of the shoulder is 40 mm or more and 55 mm or less, the axial length from the outer peripheral edge of the shoulder to the bottom of the reduced diameter portion where the diameter reduction is the largest in the reduced diameter portion is 12 mm or more and 25 mm or less, and the ratio of the diameter of the bottom of the reduced diameter portion to the diameter of the outer peripheral edge of the shoulder is 0.80 or more and 0.93 or less.

Description

Technical Field

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

[0002] Conventionally, a resin peeling container having a double-layer structure of an inner layer and an outer layer has been known, and as the content is discharged, the inner layer gradually peels off from the outer layer. Such a peeling container is also called a stratified bottle or a vacuum bottle, and is used, for example, as a container for a dressing liquid such as soy sauce or a lotion for cosmetics.

[0003] Currently, in the manufacture of such a peeling container, generally, an extrusion blow molding method is used, and the use of a stretch blow molding method is less (see Patent Document 1).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent No. 5267901 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] For example, from the viewpoints of improving the appearance, dimensional accuracy, physical property strength, etc. of the peeling container and suppressing unnecessary materials to reduce the environmental load, in the manufacture of the peeling container, a hot parison type blow molding method that continuously performs a step from an injection molding process to a blow molding process has been studied.

[0009] However, in most peeling containers, the melting point of the resin material for the outer layer is set higher than the melting point of the resin material for the inner layer. In the injection molding process of molding the double-layer preform, if the resin material for the high-temperature outer layer is filled after forming the inner layer, the surface of the inner layer in contact with the resin material for the outer layer will melt and thermally deform. Therefore, it is extremely difficult to manufacture a peeling container by applying a hot parison type blow molding method.

[0010] In addition, for example, when a peeling container having a pump member attached to its neck is held with one hand, a shape that takes into account the graspability of the container is preferable. On the other hand, the shape of the peeling container also needs to consider the moldability of the container and the ease of peeling of the inner layer.

[0011] Therefore, the present invention has been completed in view of such problems, and an object thereof is to provide a peeling container that takes into account the moldability of the container, the ease of peeling of the inner layer, and improves the graspability of the container when held with one hand.

[0012] Technical Means for Solving the Problems

[0013] The peeling container according to one embodiment of the present invention has: an outer layer formed of a first resin material; and a bag-shaped inner layer disposed on the inner peripheral side of the outer layer, formed of a second resin material different from the first resin material, and a hole for introducing air between the outer layer and the inner layer is provided in the outer layer. The peeling container includes: a neck having an opening communicating with the inside of the inner layer; a shoulder continuous from the neck and expanding radially; a bottomed cylindrical body portion; and a necking portion connecting the shoulder and the body portion. The diameter of the outer peripheral edge of the shoulder is 40 mm or more and 55 mm or less, the axial length from the outer peripheral edge of the shoulder to the bottom of the necking portion where the diameter reduction is the largest in the necking portion is 12 mm or more and 25 mm or less, and the ratio of the diameter of the bottom of the necking portion to the diameter of the outer peripheral edge of the shoulder is 0.80 or more and 0.93 or less.

[0014] Advantages of the Invention

[0015] According to one embodiment of the present invention, it is possible to consider the molding of the container and the ease of peeling of the inner layer, and improve the grip of the container under one-handed holding. Description of the Drawings

[0016] Figure 1 is a longitudinal sectional view of the preform of the present embodiment.

[0017] Figure 2 (a) of is a front view of the peeling container of the present embodiment, and (b) is a bottom view of the peeling container of the present embodiment.

[0018] Figure 3 is a longitudinal sectional view of the peeling container of the present embodiment.

[0019] Figure 4 is a diagram schematically showing the structure of the blow molding apparatus of the present embodiment.

[0020] Figure 5 is a diagram showing the manufacturing process of the preform of the present embodiment.

[0021] Figure 6 (a) of shows a view near the bottom of the first layer in the first injection molding section, and (b) is a view near the bottom of the preform in the second injection molding section.

[0022] Figure 7 is a perspective view showing a structural example of the second cavity mold of the first injection molding section. 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 the sake of easy understanding of the description, structures or elements other than the main parts of the present invention are simplified or omitted. In addition, in the drawings, the same reference numerals are assigned to the same elements. In addition, the shapes, dimensions, etc. of the respective elements shown in the drawings are schematically represented and do not represent actual shapes, dimensions, etc.

[0025] <Example Structure of Preform>

[0026] First, refer to Figure 1 to describe an example structure of a preform for a peelable container according to the present embodiment. Figure 1 is a longitudinal sectional view of the preform 10 of the present embodiment. The overall shape of the preform 10 is a bottomed cylindrical shape with one end open and the other end closed. The preform 10 includes: a trunk portion 14 formed in a cylindrical shape; a bottom portion 15 closing the other end side of the trunk portion 14; and a neck portion 13 formed at the opening on one end side of the trunk portion 14.

[0027] The preform 10 has a double-layer structure in which a second layer (inner layer) 12 is laminated inside a first layer (outer layer) 11. The first layer 11 and the second layer 12 are formed of different thermoplastic resin materials by two-stage injection molding as described later. The first layer 11 is made of a synthetic resin having excellent moldability and transparency. On the other hand, the second layer 12 is made of a synthetic resin having properties (for example, 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 first layer 11 is selected to have a higher melting point than the resin material of the second layer 12.

[0028] Hereinafter, the resin material of the first layer 11 is also referred to as the first resin material, and the resin material of the second 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 (cyclohexanedimethanol 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), 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, being about 245 to 260 °C.

[0031] In addition, in the trunk portion 14 of the preform 10, it is preferable that the ratio (t1 / t2) of the thickness t1 of the first layer 11 to the thickness t2 of the second layer 12 is 1.5 or more. From the viewpoint of ensuring the transparency of the formed peeling container, it is preferable that this thickness ratio is 3.0 or less.

[0032] In addition, in the bottom portion 15 of the preform 10, an opening 16 is formed penetrating the first layer 11 at the center of the bottom of the first layer 11. The opening 16 of the first layer 11 is blocked from the inside by the second layer 12.

[0033] In addition, in the bottom portion 15 of the preform 10, a recess 17 for forming an air introduction hole in the peeling container is formed. The recess 17 has, for example, a circular cross-section, and at least one is formed at intervals in the radial direction from the center of the bottom portion 15 of the preform 10, but a plurality of recesses 17 may be formed in the circumferential direction. The depth of the recess 17 in the thickness direction of the preform is set to a size such that at least the recess 17 penetrates the first layer 11 and the surface of the second layer 12 is exposed within the recess 17. In addition, the recess 17 formed in the double-layer preform 10 may be distinguished from the recess (described later) formed only in the first layer 11 and referred to as a second recess. In addition, the cross-section of the recess 17 may be an elliptical shape, a polygonal shape, a slit shape, or a shape formed by combining them, in addition to a circular shape.

[0034] <Example of the structure of the peeling container>

[0035] Next, with reference to Figure 2 、 Figure 3 An example of the structure of the resin peeling container 20 according to the present embodiment will be described. Figure 2 Figures (a) and (b) are a front view and a bottom view of the peeling container 20 of the present embodiment. Figure 3 is a longitudinal sectional view of the peeling container 20 of the present embodiment.

[0036] The peeling container 20 is a bottle-shaped resin container obtained by stretch blow molding of the preform 10, and stores, for example, a seasoning liquid such as soy sauce. In addition, the use of the peeling container 20 may also be to store other contents such as a cosmetic liquid for cosmetics.

[0037] As shown in Figure 2As shown by the dashed line in (a) below, on the neck 21 of the peeling container 20 described below, a nozzle head 60, which is an example of a pump component, is installed in an airtight state to seal the container. The nozzle head 60 discharges a predetermined amount of the content of the container from the nozzle in response to an operation of pressing the top portion.

[0038] As Figure 3 shown, the peeling container 20, like the preform 10, has a double-layer structure in which a bag-shaped second layer 12 is laminated inside the first layer 11. In the trunk portion 22 of the peeling container 20, the ratio (t11 / t12) of the thickness t11 of the first layer 11 to the thickness t12 of the second layer 12 is substantially the same as the thickness ratio (t1 / t2) in the trunk portion 14 of the preform 10.

[0039] As Figure 2 shown in (a) below, the peeling container 20 has: a neck 21 having an opening at the upper end; a cylindrical trunk portion 22 continuous from the neck 21; and a bottom 23 continuous from the trunk portion 22. The trunk portion 22 includes: a shoulder portion 22a having one end connected to the neck 21 and expanding radially toward the other end; a main body portion 22c having the other end connected to the bottom 23; and a reduced neck portion 22b connecting to the other end of the shoulder portion 22a and one end of the main body portion 22c and connecting the shoulder portion 22a and the main body portion 22c. In addition, the cross-section of the peeling container 20 is substantially circular at any position in the axial direction.

[0040] The reduced neck portion 22b has: a first curved surface portion 22b1 that tapers downward (in the direction of the bottom) from the outer peripheral edge of the shoulder portion 22a; and a second curved surface portion 22b2 that tapers upward (in the direction of the neck) from one end of the main body portion 22c. The diameter of the reduced neck bottom 22b3, which connects the first curved surface portion 22b1 and the second curved surface portion 22b2 and has the largest diameter reduction in the reduced neck portion 22b, is smaller than the diameter of the other end of the shoulder portion 22a (the outer peripheral edge of the shoulder portion 22a) and the diameter of the main body portion 22c.

[0041] The diameter of the outer peripheral edge of the shoulder portion 22a, the diameter of the reduced neck bottom 22b3 in the reduced neck portion 22b, the axial dimension from the outer peripheral edge of the shoulder portion 22a to the reduced neck bottom 22b3, the axial dimension from the outer peripheral edge of the shoulder portion 22a to the top of the nozzle head 60, etc. are set to specifications that allow the container to be held with one hand and the nozzle head 60 to be operated. For example, the peeling container 20 is configured such that the thumb and middle finger are placed on the first curved surface portion 22b1 of the reduced neck portion 22b for support, and the nozzle head 60 can be pressed with the index finger.

[0042] In the case of the above use, when the nozzle head 60 is pressed with the index finger, a downward force acts on the container, but the shoulder 22a protruding beyond the necking portion 22b is hooked by the thumb and middle finger supporting the necking portion 22b, generating an upward reaction force. Thus, even when the nozzle head 60 is pressed, the container can be stably supported with one hand, improving the usability of the container. Additionally, since there is no need to firmly hold the container when discharging the content, the force on the finger supporting the container and the finger pressing the nozzle head 60 can also be reduced.

[0043] Furthermore, the radius of curvature (R value) of the first curved surface portion 22b1 is smaller than that of the second curved surface portion 22b2. That is, the necking portion 22b is shaped such that it bends significantly at the first curved surface portion 22b1 near the shoulder 22a and bends more gently at the second curved surface portion 22b2 near the main body portion 22c than the first curved surface portion 22b1.

[0044] In this way, if the radius of curvature of the first curved surface portion 22b1 is reduced, the fingers supporting the necking portion 22b will not slide and are easily caught on the shoulder 22a, making it easier to support the container. Additionally, by providing the second curved surface portion 22b2, it is easier for the thumb, middle finger, and even the ring finger to cooperate with the necking portion 22b, thus making the support and operation of the container with one hand easier.

[0045] As described above, in the case of peeling off the container 20 by supporting the necking portion 22b with the thumb and middle finger and pressing the nozzle head 60 with the index finger, considering the ease of one-handed grasping and the functionality as a peeling container, it is preferable to satisfy the following dimensional conditions. For example, the diameter (φ1) of the outer peripheral edge of the shoulder 22a is 40 mm or more and 55 mm or less, and the axial length (L1) from the position of the outer peripheral edge of the shoulder 22a to the position of the bottom of the necking of the necking portion 22b is 12 mm or more and 25 mm or less. Additionally, the ratio (φ2 / φ1) of the diameter (φ2) of the bottom of the necking of the necking portion 22b to the diameter (φ1) of the outer peripheral edge of the shoulder 22a is in the range of 0.80 or more and 0.93 or less.

[0046] The diameter φ2 of the bottom 22b3 of the necking portion 22b supported by the thumb and middle finger can be defined by the diameter φ1 of the outer peripheral edge of the shoulder 22a and the ratio (φ2 / φ1) of the diameter φ2 of the bottom 22b3 of the necking portion 22b to the diameter φ1 of the outer peripheral edge of the shoulder 22a. If the diameter φ2 of the bottom of the necking is large, it is difficult to grip and support the container with the thumb and middle finger, reducing the usability of the container. Additionally, since the thumb and middle finger are attached to the first curved surface portion 22b1 of the necking portion 22b, the axial length L1 from the position of the outer peripheral edge of the shoulder 22a to the position of the bottom 22b3 of the necking of the necking portion 22b is preferably in the range of 12 mm or more and 25 mm or less from an ergonomic perspective.

[0047] In addition, the smaller the ratio of φ2 / φ1 described above, the easier it is for the fingers gripping the bottom of the necking to get stuck on the shoulder 22a. On the other hand, if the ratio of φ2 / φ1 is decreased and the shape is such that the shoulder 22a protrudes relatively largely from the bottom of the necking, it becomes difficult to shape the stripping container 20 during blow molding, and it is also possible that the inner layer (the second layer 12) is difficult to peel off from the outer layer (the first layer 11) at the part where the shoulder 22a protrudes when using the stripping container 20. From the above viewpoints, by setting the ratio of φ2 / φ1 in the range of 0.80 or more and 0.93 or less, it is possible to ensure the ease of gripping the container and suppress molding defects of the stripping container 20 and peeling defects of the inner layer.

[0048] Moreover, in order to easily perform the operation of pressing the nozzle head 60 with the index finger in a state where the necking part 22b is supported by the thumb and the middle finger, it is preferable that the axial interval L2 from the top of the nozzle head 60 before pressing to the outer peripheral edge of the shoulder 22a is 65 mm or less.

[0049] In the manufacture of the stripping container 20, the trunk part 22 and the bottom part 23 of the stripping container 20 are shaped by stretch blow molding to expand the trunk part 14 and the bottom part 15 of the preform 10. In addition, during stretch blow molding, by stretching the concave part 17 of the preform 10, as Figure 2 shown in (b) of, at least one air introduction hole 24 penetrating the first layer 11 is formed in the bottom part 23 of the stripping container 20.

[0050] The air introduction hole 24 preferably has a diameter of 0.5 mm or more and a circular or elliptical shape. In addition, it is preferable that a plurality of (for example, 4 or more) air introduction holes 24 are formed in the bottom part 23 of the stripping container 20. In addition, the plurality of air introduction holes 24 are preferably arranged radially with respect to the center (gate part) of the bottom part 23 of the stripping container 20. In the case of forming a plurality of air introduction holes 24, each air introduction hole 24 may be formed to be point-symmetrical with respect to the center of the bottom part 23, or may be arranged at a position deviating from the point-symmetrical position. In addition, in Figure 2 the (b) of, an example in which 4 air introduction holes 24 are arranged in a point-symmetrical manner is shown.

[0051] In the stripping container 20, the content is filled in the space inside the second layer 12. In the stripping container 20, when the content is discharged from the second layer 12 by pressing the nozzle head 60, air gradually flows into the space between the first layer 11 and the second layer 12 from the air introduction hole 24, and the first layer 11 and the second layer 12 are gradually peeled off. As a result, it is possible to replace the volume occupied by the content in the container with air without the content in the second layer 12 coming into contact with the air, and it is possible to discharge the content filled in the second layer 12 to the outside of the container.

[0052] In addition, at the center of the bottom 23 of the peeling container 20, an opening 25 (non-laminated portion, single-layer portion) that penetrates the first layer 11 is formed in the same manner as the preform 10. In the opening 25, the material of the second layer 12 fills the opening 25 by blocking it, and near the opening 25 at the bottom 23 of the peeling container 20, the second layer 12 is in a state of being exposed to the outside of the first layer 11. By the second layer 12 being exposed to the outside of the first layer 11 in the opening 25 of the peeling container 20, the second layer 12 is partially fixed to the first layer 11, and the positional deviation of the second layer 12 with respect to the first layer 11 is suppressed.

[0053] <Explanation of the manufacturing apparatus for the peeling container>

[0054] Figure 4 It is a diagram schematically showing the structure of the blow molding apparatus 30 of the present embodiment. The blow molding apparatus 30 of the present embodiment is an example of a manufacturing apparatus for 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.

[0055] 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 by the same given angle (for example, 60 degrees) each time around the conveying mechanism 37. In addition, the blow molding apparatus 30 may be configured to omit the first temperature adjustment section 32 (in this case, each molding station is arranged at a position that rotates by 72 degrees each time around the conveying mechanism 37). Further, 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.

[0056] (Conveying mechanism 37)

[0057] The conveying mechanism 37 includes Figure 4 a rotating plate (transfer plate) 37a that rotates about an axis perpendicular to the plane of the paper. On the rotating plate 37a, a neck mold 37b that holds the neck 13 of the preform 10 (or the neck 21 of the peeling container 20) (in Figure 4One or more are respectively arranged at given intervals (not shown in the figure). The conveying mechanism 37 conveys the preform 10 (or the stripping container 20) held by the neck mold 37b in the order of the first injection molding section 31, the second injection molding section 33, the second temperature adjustment section 34, the blow molding section 35, and the take-out section 36 by rotating the rotating plate 37a. In addition, the conveying mechanism 37 can also lift the rotating plate 37a, and also performs the actions of closing and opening (demolding) the molds on the first injection molding section 31 and the second injection molding section 33.

[0058] (The first injection molding section 31)

[0059] The first injection molding section 31 includes a cavity mold 40, a core mold 41, and a hot runner mold 42, and cooperates with the neck mold 37b conveyed during molding to manufacture the first layer 11 of the preform 10. The cavity mold 40 is composed of a first cavity mold 40A on the opening side (upper side) and a second cavity mold 40B on the bottom surface side (lower side). A first injection device 38 for supplying the first resin material to the hot runner mold 42 is connected to the first injection molding section 31. The cavity mold 40 and the hot runner mold 42 are fixed to the machine table of the blow molding device 30 in an integrated state. The core mold 41 is fixed to the core mold lifting mechanism.

[0060] Figure 5 Figures (a) and (b) show the first injection molding section 31 for molding the first layer 11 of the preform 10 of the present embodiment. Figure 6 Figure (a) shows a view near the bottom of the first layer 11 in the first injection molding section 31. Figure 7 It is a perspective view showing a structural example of the cavity mold 40 (second cavity mold 40B) of the first injection molding section 31.

[0061] The cavity mold 40 defines (delimits) the shape of the outer periphery of the first layer 11. The first cavity mold 40A is a mold facing the opening side of the cavity mold 40 (the side that abuts against the neck mold 37b when the mold is closed), and defines the shape of the outer periphery of the trunk of the first layer 11. The second cavity mold 40B is a mold facing the bottom surface side of the cavity mold 40 (the side that abuts against the hot runner mold 42), and defines the shape of the outer periphery of the bottom of the first layer 11. The second cavity mold 40B also includes a gate portion 40Ba for guiding the resin material from the hot runner mold 42 to the cavity surface. In addition, the hot runner mold 42 has a resin supply portion 42a for introducing the first resin material plasticized (melted) by the first injection device 38 into the second cavity mold 40B. The core mold 41 is a mold that defines the shape of the inner peripheral side of the first layer 11 and is inserted into the inner peripheral side of the cavity mold 40 from the upper side. In addition, the neck mold 37b conveyed during molding defines the outer shape of the neck 13 of the preform 10 (first layer 11).

[0062] As Figure 5As shown in (a) and (b) of , 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 first layer 11. Then, the first resin material is introduced into the mold space from the bottom through the hot runner mold 42, and the first layer 11 of the preform 10 is manufactured in the first injection molding section 31.

[0063] On the upper surface side (cavity surface side) of the second cavity mold 40B facing the outer periphery of the bottom of the first layer 11, a cylindrical (or conical cylindrical, square cylindrical) first protrusion 44 is provided at a given position. As Figure 7 shown in (a) of , at least one first protrusion 44 is arranged at intervals in the radial direction from the center of the bottom where the resin supply section 42a is located. As Figure 6 shown in (a) of , the protruding amount h1 of the first protrusion 44 with respect to the cavity reference surface of the second cavity mold 40B (the cavity surface that defines the lower end side shape of the outer periphery of the bottom of the first layer 11) is approximately the same size as the thickness of the first layer 11. Therefore, when the first injection molding section 31 is closed, the front end of the first protrusion 44 faces the surface of the core mold 41 (near the surface arranged on the core mold 41). Thus, in the injection molding of the first injection molding section 31, through the first protrusion 44, a concave portion 11a such as a circle is formed in the first layer 11 at a position corresponding to the concave portion 17 of the preform 10. The concave portion 11a of the first layer 11 may penetrate the first layer 11 or may have a film formed by being clamped between the core mold 41 and the first protrusion 44. In addition, the concave portion 11a of the first layer 11 formed by the first injection molding section 31 is also referred to as the first concave portion.

[0064] In addition, as Figure 5 shown in (b) of , a valve pin 43 (a rod-shaped member that opens and closes the resin supply section 42a) capable of moving axially to a position close to the core mold 41 is provided at the resin supply section 42a of the hot runner mold 42. The valve pin 43 is housed inside the hot runner mold 42 before the first resin material is filled into the mold space, and after the first resin material is filled into the mold space, it protrudes to a position closer to the core mold 41 than the opening end of the cavity of the gate portion 40Ba. By such movement of the valve pin 43 during injection molding, a film portion 18 with a thinner wall thickness at the center of the bottom of the first layer 11 than at the peripheral portion can be formed.

[0065] 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 first 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 (that is, the number of peeling containers 20 that can be simultaneously molded by the blow molding device 30) can be appropriately set.

[0066] (First temperature adjustment section 32)

[0067] The first temperature adjustment unit 32 includes a temperature adjustment die (not shown) (a heating tank or a temperature adjustment tank (temperature control tank) for externally adjusting the temperature of the first layer 11, and a heating rod, a temperature adjustment rod (temperature control rod), or an air introduction rod for internally adjusting the temperature of the first layer 11). The first temperature adjustment unit 32 cools (or heats) the first layer 11 in a high-temperature state after injection molding by accommodating it in the temperature adjustment die maintained at a given temperature. In addition, the first temperature adjustment unit 32 also functions to adjust the temperature distribution of the first layer 11 to a given state before being conveyed to the second injection molding unit 33.

[0068] (Second injection molding unit 33)

[0069] The second injection molding unit 33 includes a cavity die 50, a core die 51, and a hot runner die 52, and cooperates with the neck die 37b conveyed during molding to injection mold the second layer 12 on the inner peripheral side of the first layer 11. The cavity die 50 is composed of a first cavity die 50A on the opening side (upper side) and a second cavity die 50B on the bottom side (lower side). A second injection device 39 for supplying the second resin material to the hot runner die 52 is connected to the second injection molding unit 33.

[0070] Figure 5 (c) of shows the second injection molding unit 33 for molding the second layer 12 of the preform 10. Figure 6 (b) is a view showing the vicinity of the bottom of the preform 10 in the second injection molding unit 33.

[0071] The cavity die 50 is a die for accommodating the first layer 11. The first cavity die 50A is a die facing the opening side of the cavity die 50 and accommodates the trunk of the first layer 11. The second cavity die 50B is a die facing the bottom side of the cavity die 50 and accommodates the bottom of the first layer 11. The second cavity die 50B also includes a gate portion 50Ba for guiding the resin material from the hot runner die 52 to the cavity surface. In addition, the hot runner die 52 has a resin supply portion 52a for introducing the second resin material plasticized (melted) by the second injection device 39. The core die 51 is a die for defining the shape of the inner peripheral side of the second layer 12 and is inserted into the inner peripheral side of the cavity die 50 from the upper side. In addition, the neck die 37b conveyed during molding defines the upper end surface (top surface) of the neck 13 of the preform 10 (second layer 12). Furthermore, the hot runner die 52 may have a structure with a valve pin like the hot runner die 42. However, the position of the valve pin when closing the second resin material is set so as not to protrude from the opening end of the cavity of the gate portion 50Ba.

[0072] As Figure 5As shown in (c) of the figure, the second injection molding section 33 houses the first 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 peripheral side of the first layer 11 and the surface of the core mold 51. In the second injection molding section 33, by flowing the second resin material into the mold space from the bottom through the hot runner mold 52, a preform 10 is formed in which a second layer 12 is laminated on the inner peripheral side of the first layer 11.

[0073] In addition, on the upper surface side (cavity surface side) of the second cavity mold 50B facing the outer periphery of the bottom of the first layer 11, at a given position corresponding to the first protrusion 44 of the first injection molding section 31, a second protrusion 54 having a cylindrical shape or the like corresponding to the shape of the concave portion 17 of the preform 10 is provided. When the first layer 11 is housed in the second injection molding section 33, the second protrusion 54 is inserted through the concave portion 11a of the first layer 11. Thus, the basic structure of the protrusion and the like in the second cavity mold 50B is substantially the same as that of the second cavity mold 40B of the first injection molding section 31.

[0074] Here, as Figure 6 shown in (b) of the figure, the protruding amount h2 of the second protrusion 54 from the cavity reference surface of the second cavity mold 50B (the cavity surface in contact with the lower end side region of the outer peripheral surface of the bottom of the first layer 11) is a size larger than the thickness of the first layer 11. That is, the protruding amount h2 of the second protrusion 54 is greater than the protruding amount h1 of the first protrusion 44 (h2 > h1). Therefore, when the second injection molding section 33 is closed, the front end of the second protrusion 54 penetrates through the concave portion 11a of the first layer 11 and protrudes to the inner peripheral side of the first layer 11. By providing the second protrusion 54 on the second cavity mold 50B of the second injection molding section 33, a concave portion 17 can be formed at the bottom 15 of the preform 10.

[0075] In addition, the protruding amount h2 of the second protrusion 54 is set to be smaller than the thickness of the preform 10. That is, in the injection molding of the second injection molding section 33, since the second resin material flows between the core mold 51 and the second protrusion 54, a hole penetrating through the second layer 12 is not formed by the second protrusion 54.

[0076] (Second Temperature Adjusting Section 34)

[0077] The second temperature adjustment unit 34 includes a mold unit for temperature adjustment (not shown) (a heating tank or a temperature adjustment tank (temperature control tank) that adjusts the temperature of the preform 10 from the outside, and a heating rod, a temperature adjustment rod (temperature control rod), or an air introduction rod that adjusts the temperature of the preform 10 from the inside). The second temperature adjustment unit 34 equalizes the temperature or eliminates temperature deviation by housing the preform 10 conveyed from the second injection molding unit 33 in the mold unit maintained at a given 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 unit 34 also functions to cool the preform 10 in the high-temperature state after injection molding.

[0078] (Blow molding unit 35)

[0079] The blow molding unit 35 blow-molds the preform 10 whose temperature has been adjusted by the second temperature adjustment unit 34 to manufacture the peeling container 20.

[0080] The blow molding unit 35 includes a pair of split molds corresponding to the shape of the peeling container 20, namely, a blow molding cavity mold, a bottom mold, a stretching rod, and an air introduction component (all not shown). The blow molding unit 35 performs blow molding while stretching the preform 10. Thus, the preform 10 can be shaped into the shape of the blow molding cavity mold to manufacture the peeling container 20.

[0081] (Take-out unit 36)

[0082] The take-out unit 36 is configured to open the neck 21 of the peeling container 20 manufactured by the blow molding unit 35 from the neck mold 37b and take out the peeling container 20 to the outside of the blow molding apparatus 30.

[0083] <Explanation of the container manufacturing method>

[0084] Next, a method for manufacturing the peeling container 20 by the blow molding apparatus 30 according to the present embodiment will be described.

[0085] (Step S101: First injection molding process)

[0086] First, as shown in (a) of Figure 5 , in the first injection molding unit 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 mold the first layer 11 of the preform 10. At this time, through the first protrusion 44, a recess 11a is formed at the bottom of the first layer 11.

[0087] In the first injection molding unit 31, as shown in Figure 5As shown in (b) of , after forming the first layer 11 of the preform 10, a process is performed to project the valve pin 43 to a position close to the core mold 41. As a result, a film portion 18 having a wall thickness thinner than that of the peripheral portion is formed at the center of the bottom of the first layer 11.

[0088] After that, the first injection molding section 31 is opened, and the first layer is demolded. When the first injection molding section 31 is opened, the rotating plate 37a of the conveying mechanism 37 rotates by a given angle, and the first layer 11 of the preform 10 held by the neck mold 37b is conveyed to the first temperature adjusting section 32 while maintaining the heat retained during injection molding.

[0089] (Step S102: First temperature adjustment process)

[0090] Next, in the first temperature adjusting section 32, the first layer 11 of the preform 10 is housed in a temperature adjusting mold, and cooling of the first layer 11 and adjustment of the temperature distribution (equalization of temperature, elimination of temperature deviation) are performed. In addition, the first temperature adjustment process may be omitted.

[0091] After the first temperature adjustment process (or the first injection molding process), the rotating plate 37a of the conveying mechanism 37 rotates by a given angle, and the temperature-adjusted first layer 11 held by the neck mold 37b is conveyed to the second injection molding section 33.

[0092] (Step S103: Second injection molding process)

[0093] Next, the first layer 11 of the preform 10 is housed in the second injection molding section 33, and the second layer 12 is injection molded.

[0094] In the second injection molding section 33, as Figure 5 shown in (c) of , a mold space is formed between the inner peripheral side of the first layer 11 and the surface of the core mold 51 facing the inner periphery of the first layer 11, and a second resin material is filled into the mold space from the hot runner mold 52. In addition, a film portion 18 is formed at the bottom of the first layer 11, but the film portion 18 is broken due to the injection pressure of the second resin material, and an opening portion 16 is formed at the bottom, and the second resin material is guided from the opening portion 16 to the inner peripheral side of the first layer 11.

[0095] 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 first layer 11 when the second resin material is filled in the second injection molding section 33 is cooled to a temperature lower than the melting point of the second resin material.

[0096] In the second injection molding section 33, the cavity mold 50 faces the outer peripheral side of the first layer 11, and the shape of the first layer 11 is held from the outer peripheral side by the cavity mold 50. Therefore, even if the second resin material comes into contact with the first layer 11, thermal deformation of the first layer 11 can be suppressed.

[0097] In addition, in the second injection molding section 33, since the second protrusion 54 penetrates and blocks the recess 11a of the first layer 11, the recess 17 of the preform 10 will not be blocked by the second resin material. In addition, since the front end of the second protrusion 54 in the second injection molding section 33 protrudes to the inner peripheral side of the first layer, the recess 17 of the preform 10 formed by the second protrusion 54 becomes a shape that penetrates the first layer 11 and exposes the surface of the second layer 12 in the recess 17.

[0098] As described above, through the first injection molding process and the second injection molding process, the preform 10 with the second layer 12 laminated on the inner peripheral side of the first layer 11 is manufactured.

[0099] After that, when the second injection molding section 33 is opened, the rotating plate 37a of the conveying mechanism 37 rotates by a given angle, and the preform 10 held by the neck mold 37b is conveyed to the second temperature adjusting section 34 while maintaining the heat retained during injection molding.

[0100] (Step S104: Second temperature adjusting process)

[0101] Next, in the second temperature adjusting section 34, the preform 10 is housed in a mold unit for temperature adjustment, and temperature adjustment is performed to make the temperature of the preform 10 close to the temperature suitable for final blow molding. After that, the rotating plate 37a of the conveying mechanism 37 rotates by a given angle, and the temperature-adjusted preform 10 held by the neck mold 37b is conveyed to the blow molding section 35.

[0102] (Step S105: Blow molding process)

[0103] Next, in the blow molding section 35, blow molding of the peeling container 20 is performed.

[0104] 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 member 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. As a result, the preform 10 bulges out 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.

[0105] (Step S106: Container taking-out process)

[0106] When the blow molding is completed, the blow molding cavity mold is opened. Thus, the peeling container 20 can move from the blow molding section 35.

[0107] Next, the rotating plate 37a of the conveying mechanism 37 rotates by a given angle, and the peeling container 20 is conveyed to the take-out section 36. In the take-out section 36, the neck 21 of the peeling container 20 is opened from the neck mold 37b, and the peeling container 20 is taken out to the outside of the blow molding apparatus 30.

[0108] Thus, one cycle of the manufacturing method of the peeling container ends. Thereafter, by rotating the rotating plate 37a of the conveying mechanism 37 by a given angle, the respective steps of S101 to S106 described above are repeated. Further, when the blow molding apparatus 30 is operating, six sets of manufacturing of the peeling containers 20 with a time difference of one step each are executed in parallel.

[0109] In addition, in the structure of the blow molding apparatus 30, the standby times of the first injection molding step, the first temperature adjustment step, the second injection molding step, the second temperature adjustment step, the blow molding step, and the container take-out step are respectively of the same length. Similarly, the conveyance times between the respective steps are also respectively of the same length.

[0110] Hereinafter, the effects of the blow molding apparatus and the blow molding method of the present embodiment will be described.

[0111] In the present embodiment, in the first injection molding step, the first layer 11 (outer layer) of the preform 10 is molded, and in the second injection molding step, the second layer 12 (inner layer) is injection molded inside the first layer 11 from the opening 16 of the first layer 11 to manufacture the double-layer preform 10. According to the present embodiment, the outer layer can be formed first with a resin material having a high melting point, and then the inner layer can be formed with a resin material having a lower melting point than the outer layer. That is, the inner layer is continuously injection molded in a state where the outer layer retains heat during injection molding, and the double-layer preform 10 suitable for the specifications of the peeling container 20 can be manufactured. In the present embodiment, since the double-layer preform 10 is demolded in a state where both the outer layer and the inner layer retain heat during injection molding, a suitable preform 10 can be obtained when manufacturing the peeling container 20 by the hot preform blow molding method.

[0112] Moreover, in the present embodiment, in a state where heat is retained during injection molding, the above-described double-layer preform 10 is stretch blow molded to manufacture the peeling container 20. Therefore, in the present embodiment, it is possible to manufacture a peeling container 20 with excellent appearance, physical properties, strength, etc. by a hot preform type blow molding method. Compared with the cold preform type blow molding, in the present embodiment, it is not necessary to cool the manufactured preform 10 to near room temperature, nor is it necessary to reheat the preform 10. Therefore, according to the present embodiment, a series of processes from the injection molding of the preform 10 to the blow molding of the peeling container 20 can be completed in a relatively short time, and the peeling container 20 can be manufactured in a shorter cycle.

[0113] In addition, in the present embodiment, in the first injection molding process, the recess 11a is formed in the first layer 11 by the first protrusion 44. Then, in the second injection molding process, the second protrusion 54 having a larger protrusion amount than the first protrusion 44 penetrates the recess 11a of the first layer 11, and the recess 17 is formed at the bottom 15 of the preform 10. Thus, in the peeling container 20, the air introduction hole 24 that penetrates the first layer 11 and reaches the surface of the second layer 12 can be reliably formed.

[0114] 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.

[0115] In the above-described embodiment, an example in which one recess 17 is provided at the bottom 15 of the preform 10 has been described, but for example, the number of recesses 17 formed may also be plural. Figure 7 (b) shows an example in which the first protrusions 44 are provided at two positions in the second cavity mold 40B of the first injection molding section 31. In Figure 7 the example of (b), the two first protrusions 44 are arranged at positions that are point-symmetric with respect to the central axis at an interval of 180°. In addition, the number of the first protrusions 44 may also be three or more. In this case, each of the first protrusions 44 is preferably arranged in a point-symmetric positional relationship with respect to the central axis.

[0116] According to the above structure, the circumferential non-uniformity of the resin flow during injection molding is further reduced. In addition, in the case of the above structure, in the second injection molding section 33, it is also necessary to arrange the second protrusion 54 at the same position as the first protrusion 44.

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

[0118] Reference Signs

[0119] 10…Preformed parison, 11…First layer, 11a…Recess, 12…Second layer, 16…Opening, 17…Recess, 18…Film part, 20…Peeling container, 24…Air inlet hole, 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, 38…First injection device, 39…Second injection device, 40B, 50B…Cavity molds, 44…First protrusion, 54…Second protrusion.

Claims

1. A peeling container, comprising: an outer layer formed of a first resin material; and a bag-shaped inner layer provided on the inner peripheral side of the outer layer and formed of a second resin material different from the first resin material. A hole for introducing air between the outer layer and the inner layer is provided in the outer layer, wherein, The peeling container includes: a neck having an opening communicating with the inside of the inner layer; a shoulder continuous with the neck and extending radially; a bottomed cylindrical body portion; and a reduced neck portion connecting the shoulder and the body portion, The cross-section of the peeling container in a direction orthogonal to the axial direction is circular, The diameter of the outer peripheral edge of the shoulder is 40 mm or more and 55 mm or less, The axial length from the outer peripheral edge of the shoulder to the reduced neck bottom where the diameter reduction degree is the largest in the reduced neck portion is 12 mm or more and 25 mm or less, The ratio of the diameter of the reduced neck bottom to the diameter of the outer peripheral edge of the shoulder is 0.80 or more and 0.93 or less.

2. The peeling container according to claim 1, wherein, The reduced neck portion has: a first curved surface portion connected to the shoulder and reducing in diameter toward the reduced neck bottom; and a second curved surface portion connected to the body portion and reducing in diameter toward the reduced neck bottom, The radius of curvature of the first curved surface portion is smaller than the radius of curvature of the second curved surface portion.

3. The peeling container according to claim 1, wherein, A pump member for discharging the filler in the inner layer by pressing the top is installed on the neck, The axial length from the top of the pump member to the outer peripheral edge of the shoulder is 65 mm or less.

4. A method for manufacturing a peeling container, which is a method for manufacturing the peeling container according to any one of claims 1 to 3, and has: A first injection molding step of injection molding a first layer of a bottomed cylindrical preform with a first resin material; A second injection molding step of injecting a second resin material different from the first resin material and laminating a second layer on the inner peripheral side of the first layer; and A blow molding step of blow molding the preform obtained in the second injection molding step in a state of retaining heat during injection molding to manufacture the peeling container, In the first injection molding step, a first concave portion formed by a first protrusion portion is formed in at least a part of the first layer, In the second injection molding step, a second concave portion is formed in the preform by inserting a second protrusion portion into the first concave portion. The second concave portion penetrates the first layer and exposes the surface of the second layer, In the blow molding step, the second concave portion is stretched to form an air introduction hole in the outer layer of the peeling container.

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