Preform, method for manufacturing resin container, and apparatus for manufacturing resin container

Abstract

A preform (20) for manufacturing a resin container provided with a container head, a container main body, and a container bottom, the preform being provided with an annular neck (21) constituting the container head and a main body (22) constituting the container main body and the container bottom, the angle (theta) formed by the central axis (X) of the neck (21) and the main body (22) being 80-100 degrees.

Description

Technical Field

[0001] The present disclosure relates to a preform, a method for manufacturing a resin container, and an apparatus for manufacturing a resin container. Background Art

[0002] Patent Document 1 discloses a method for producing a resin container. The resin container is produced by controlling the temperature of a preform produced by an injection molding unit to a temperature suitable for blow molding and then performing blow molding.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2021 / 221024 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In recent years, there has been a desire to reduce the amount of resin in the preforms that make up the container body and bottom of resin containers in order to reduce weight. However, when manufacturing resin containers using stretch blow molding (particularly the hot parison method), the wall thickness distribution and shape of the preform must be designed taking into account the shape of the resin container being manufactured, the required specifications (rigidity, transparency), and the expected stretching conditions. It is not possible to simply thin the preform. Furthermore, if the preform is simply thinned, manufacturing defects are likely to occur during the formation of the preform by injection molding and during demolding from the injection molding mold. Furthermore, it is difficult to adjust the temperature distribution (heat distribution) of the preform immediately before blow molding, and it is also difficult to appropriately stretch the preform during blow molding to produce a resin container with the desired shape and specifications.

[0008] An object of the present disclosure is to provide a preform, a resin container manufacturing apparatus, and a resin container manufacturing method that achieve both weight reduction and suppression of defects in manufacturing a resin container.

[0009] Solutions for solving problems

[0010] A preform according to one aspect of the present disclosure is a preform for manufacturing a resin container having a container head, a container body, and a container bottom, wherein:

[0011] The preform includes an annular neck portion constituting the container head portion and a main body portion constituting the container main body portion and the container bottom portion.

[0012] The angle formed by the central axis of the neck and the main body is 80° to 100°.

[0013] One aspect of the present disclosure is a method for manufacturing a resin container including a container head, a container body, and a container bottom, comprising:

[0014] Injection molding process, injecting molten resin into the injection cavity formed by the injection molding mold to form a first preform;

[0015] a temperature adjustment step of transforming the first preform into a second preform and adjusting the temperature to a temperature suitable for blow molding; and

[0016] a blow molding step of blow-molding the second preform to produce a resin container;

[0017] The temperature adjustment step includes: stretching the first preform so that the preform contacts the inner wall surface of the temperature adjustment cavity formed by the temperature adjustment mold, thereby forming the second preform;

[0018] In the first preform,

[0019] The container comprises an annular neck portion constituting the container head portion and a main body portion constituting the container main body portion and the container bottom portion.

[0020] The angle formed by the central axis of the neck and the main body is 80° to 100°.

[0021] A resin container manufacturing apparatus according to one aspect of the present disclosure is a resin container manufacturing apparatus that manufactures a resin container having a container head, a container body, and a container bottom, and includes:

[0022] An injection molding unit including an injection molding die, wherein the injection molding die forms an injection cavity for manufacturing a first preform;

[0023] a temperature regulating portion including a deformation portion for deforming the first preform into a second preform and a temperature regulating mold constituting a temperature regulating chamber; and

[0024] The blow molding section includes a blow molding die that defines the shape of the resin container manufactured by blow molding the second preform.

[0025] The inner wall surface of the temperature control chamber is configured to cool the first preform by contacting the first preform and to define the shape of the second preform.

[0026] The inner wall surface of the injection cavity is composed of:

[0027] In the first preform, an annular neck portion constituting the container head portion and a main body portion constituting the container main body portion and the container bottom portion are defined.

[0028] The angle formed by the central axis of the neck and the main body is 80° to 100°.

[0029] Effects of the Invention

[0030] According to the present disclosure, it is possible to provide a preform for a resin container, a resin container manufacturing apparatus, and a resin container manufacturing method that achieve both weight reduction and suppression of defects in manufacturing the resin container. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a block diagram of the manufacturing apparatus of the resin container according to the present embodiment.

[0032] Figure 2 This is a diagram showing an example of a resin container manufactured by the manufacturing apparatus of this embodiment.

[0033] Figure 3 This is a diagram showing an example of a first preform.

[0034] Figure 4 This is a diagram showing an example of a second preform.

[0035] Figure 5 This is a diagram showing an example of an injection molding portion.

[0036] Figure 6 This is a diagram showing an example of a temperature adjustment unit.

[0037] Figure 7 This is a diagram showing an example of a temperature adjustment unit.

[0038] Figure 8 This is a diagram showing an example of a blow molding section.

[0039] Figure 9 This is a diagram illustrating a method for manufacturing a resin container. DETAILED DESCRIPTION

[0040] Hereinafter, as one embodiment of the present disclosure, a manufacturing apparatus 100 and a manufacturing method for a resin container 10 will be described with reference to the drawings. For convenience of description, the dimensions of each component shown in the drawings may differ from the actual dimensions of each component.

[0041] For convenience of explanation, reference will be made to "upper and lower directions" and "left and right directions" as appropriate. Here, "upper and lower directions" include both "up" and "down." "Left and right" include both "left" and "right." In the figures described below, reference symbol U indicates the upper direction. Reference symbol D indicates the lower direction. Reference symbol L indicates the left direction. Reference symbol R indicates the right direction. Unless otherwise specified, descriptions will be made with the direction in which the first preform, second preform, and opening of the resin container are positioned as the upper direction.

[0042] Figure 1 The resin container 10 of this embodiment (see Figure 2 ) is a block diagram of a manufacturing device 100. Figure 1 As shown in the example, the manufacturing apparatus 100 is a blow molding apparatus using a hot parison method (a one-step blow molding method, an injection stretch blow molding method), and includes an injection molding unit 110, a temperature control unit 120, a blow molding unit 130, and a take-out unit 140. The injection molding unit 110 manufactures a first preform 20 (see FIG. 1 ) described later by injecting molten resin from an injection device 111. Figure 3 The temperature regulating unit 120 transforms the first preform 20 into a second preform 30 (see Figure 4 ), and the second preform 30 is temperature-controlled to a temperature suitable for blow molding. The blow molding unit 130 manufactures the resin container 10 by blow molding the second preform 30. The removal unit 140 removes the resin container 10 manufactured by the blow molding unit 130.

[0043] The injection molding section 110, the temperature control section 120, the blow molding section 130, and the removal section 140 are arranged at positions that rotate at a predetermined angle with the conveying unit 150 as the center. In this embodiment, the predetermined angle is 90 degrees. The conveying unit 150 has a rotating plate (not shown). The neck mold 151 (see FIG. 1 ) described later is installed on the rotating plate. Figure 5 The rotating plate is configured to rotate while the neck mold 151 holds the first preform 20 and the second preform 30, thereby transporting the first preform 20 and the second preform 30 to the injection molding unit 110, the temperature regulating unit 120, the blow molding unit 130, and the removal unit 140.

[0044] Figure 2 The resin container 10 manufactured by the manufacturing apparatus 100 of this embodiment is shown as an example. Figure 2 As shown in the example, the resin container 10 includes a container head 11, a container body 12, and a container bottom 13. The container head 11 forms the opening of the resin container 10. The container body 12 is connected to the container head 11 and forms the side of the resin container 10. The container bottom 13 is connected to the container body 12 and closes one end of the container body 12.

[0045] Figure 3 The first preform 20 is shown as an example. Figure 3As shown in the example, the first preform 20 includes an annular neck 21 and a main body 22. The neck 21 includes at least one annular flange portion 211 protruding in the outer diameter direction on its outer peripheral surface. The flange portion 211 includes at least a first flange portion 211a arranged between the upper end of the neck 21 and the main body 22, and, as needed, a second flange portion 211b arranged at the upper end of the neck 21 and protruding in the outer diameter direction. The first flange portion 211a is a portion supported by the neck mold 151 during manufacturing. The first flange portion 211a is a portion for fixing the cover and the sealing member. The diameter of the second flange portion 211b is preferably formed to be larger than the diameter of the first flange portion 211a. The main body 22 is connected to the lower part of the neck 21 and has a circular and roughly flat shape. The main body 22 includes at least a side portion 221 extending flush downward from the outer circumferential surface of the neck 21; a corner portion (corner portion) 222 located at the lower end of the side portion 221 and curved toward the inner diameter; and a plate-shaped portion (planar portion) 223 extending horizontally from the corner portion 222. Furthermore, a gate portion, serving as a trace of the resin inlet hole of the injection cavity mold 114, may be provided at the center of the outer surface of the plate-shaped portion 223 of the main body 22. When viewed from the side, the outer surface of the main body 22 (more specifically, the plate-shaped portion 223) is preferably approximately horizontal, but may also be curved (surface-like) with a gentle downward protrusion toward the gate portion. Furthermore, when viewed from the side, the inner surface of the main body 22 is also preferably approximately horizontal, but may also be curved (surface-like) with a gentle downward protrusion toward the gate portion. When the outer surface of the main body 22 is approximately horizontal, it is preferably formed approximately parallel to the inner surface of the main body 22. In this case, it is preferable to set the wall thickness of the main body portion, excluding the gate portion, to be substantially constant. The neck portion 21 constitutes the container head portion 11 that forms the opening of the resin container 10. The main body portion 22 constitutes the container main body portion 12 and the container bottom portion 13 of the resin container 10 by blow molding. The first preform 20 is an example of a preform.

[0046] In the present embodiment, the angle (angle) θ formed by the central axis X of the neck 21 and the main body 22 (or the outer surface or inner surface of the main body 22 (more specifically, the plate-shaped portion 223)) is approximately 90° (the outer surface of the main body 22 is regarded as a horizontal plane without the gate portion). In this case, the angle of the corner of the main body 22 is also approximately 90°. However, the main body 22 may also be formed to be inclined relative to the central axis X. The angle (angle) formed by the central axis X of the neck 21 and the main body 22 (or the outer surface or inner surface of the main body 22) is preferably 80° to 100°. In this case, the angle of the corner of the main body 22 is also preferably 80° to 100°. Therefore, the shape of the first preform 20 is a flat shape in the direction of the central axis X. In addition, the thickness of the main body 22 (more specifically, the plate-shaped portion 223) of the first preform 20 excluding the gate portion is preferably not less than 2.0 mm and not more than 6.0 mm, and more preferably not less than 3.0 mm and not more than 5 mm.

[0047] Figure 4 The second preform 30 is shown as an example. Figure 4 As shown in the example, the second preform 30 is different from the first preform 20 in that the main body 22 of the first preform 20 is a shape that protrudes downward. In other words, the second preform 30 is roughly conical. The second preform 30 may be a shape different from the second preform 30 in this embodiment as long as it is a shape suitable for blow molding in the blow molding section 130. The second preform 30 is roughly conical, and the thickness of the main body wall 32 and the bottom wall 33 is smaller (thinner) than the thickness of the main body 22 of the first preform 20. In addition, the shape and thickness of the neck 31 of the second preform 30 are the same as those of the neck 21 of the first preform 20.

[0048] The material constituting the first preform 20, the second preform 30 and the resin container 10 is a thermoplastic synthetic resin, which can be appropriately selected according to the required specifications. Specific types of materials include PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PCTA (polycyclohexanedimethanol terephthalate), Tritan (Tritan (registered trademark): a 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. In addition, additives such as coloring materials can also be added to the materials. It should be noted that the material of the first preform 20, the second preform 30 and the resin container 10 of this embodiment is most preferably PET.

[0049] Figure 5 The injection molding section 110 is shown as an example. The injection molding section 110 includes an injection molding mold 112. The injection molding mold 112 constitutes an injection cavity (molding space). The injection molding mold 112 includes at least an injection molding core 113 and an injection cavity mold 114. In addition, the injection molding mold 112 may also include a neck mold 151 that also serves as a part of the conveying unit 150 during molding (temporarily). The injection molding core 113 mainly defines an injection cavity corresponding to the inner wall surface of the first preform 20. The injection cavity mold 114, together with the neck mold 151, defines an injection cavity corresponding to the outer wall surface of the first preform 20. Specifically, the neck mold 151 defines an injection cavity corresponding to the outer wall surface of the neck 21 of the first preform 20, and the injection cavity mold 114 defines an injection cavity corresponding to the outer wall surface of the main body 22 of the first preform 20. The neck mold 151 defines an injection cavity corresponding to the flange portion 211 of the neck 21. More specifically, the neck mold 151 defines an injection cavity corresponding to the first flange portion 211a of the neck portion 21. Furthermore, the neck mold 151 and the injection molding core 113 define an injection cavity mold corresponding to the second flange portion 211b.

[0050] Figure 6 and Figure 7The temperature control section 120 is shown as an example. The temperature control section 120 includes a temperature control mold (temperature control kettle mold) 121, a cooling rod (first hollow rod member, temperature control rod) 122, and a fitting core (second hollow rod member) 124 that can be in airtight contact with the necks 21 and 31 as a temperature control mold member. In addition, the temperature control mold member may also be (temporarily) provided with a neck mold 151 that is also part of the conveying unit 150 during molding. The temperature control mold 121 constitutes a temperature control cavity. The temperature control cavity corresponds to the shape of the outer wall surface of the second preform 30. The cooling rod 122 is configured to be displaceable in the up and down directions. The fitting core 124 is configured to be in contact with the neck 21 of the first preform 20 and the neck 31 of the second preform 30, and to introduce (supply) or extract (exhaust) compressed air of a specified pressure relative to the first preform 20 or the second preform 30. The cooling rod 122 includes an abutment portion 123. The abutting portion 123 is configured to contact at least a portion of the inner wall surface of the first preform 20 and the second preform 30. The abutting portion 123 is formed of a metal material with good heat conductivity, such as aluminum or an aluminum alloy. A first air vent 123a is formed in the abutting portion 123 of the cooling rod 122. The first air vent 123a is configured to introduce (supply) compressed air of a specified pressure to the first preform 20 or the second preform 30 through the interior of the cooling rod 122. In addition, a second air vent 123b is formed between the cooling rod 122 and the interlocking core 124. The second air vent 123b is configured to lead out (exhaust) compressed air from the first preform 20 or the second preform 30. The cooling rod 122 is an example of a deformation portion. It should be noted that the temperature regulating portion 120 can also be configured to introduce compressed air of a specified pressure to the first preform 20 or the second preform 30 from the second air vent 123b, and discharge air from the first air vent 123a.

[0051] Figure 8 The blow molding section 130 is shown as an example. The blow molding section 130 includes a blow molding mold (blow mold) 131, a stretch rod 132, and a blow core mold (blow nozzle) 133 for introducing / exporting blow air as blow molding mold components. In addition, the blow molding mold component may also include a neck mold 151 that also serves as a part of the conveying unit 150 during molding (temporarily). The blow molding mold 131 is configured to define the shape of the resin container 10. The blow molding mold 131 includes: a pair of blow cavity molds 131a that can be opened and closed, which define the shape of the container body 12 of the resin container 10; and a bottom mold 131b that defines the shape of the container bottom 13 of the resin container 10. The stretch rod 132 is configured to be displaceable in the vertical direction. The stretch rod 132 is configured to contact the second preform 30 conveyed to the blow molding section 130 and stretch the second preform 30 downward. The blow core 133 abuts against the neck 31 and is responsible for introducing (supplying) and discharging (exhausting) blowing air to the second preform 30 .

[0052] Next, a method for producing a resin container will be described. Figure 9 The following is an example of a method for manufacturing a resin container. Figure 9 As exemplified above, the method for producing a resin container is a method using a hot parison method, and includes at least an injection molding step S1, a temperature control step S2, and a blow molding step S3. The production method of this embodiment further includes a container removal step S4.

[0053] like Figure 5 As shown in the example, the injection molding process S1 includes injecting molten resin into the injection cavity formed by the injection mold 112 to form the first preform 20. The molten resin injected into the injection cavity by the injection device 111 of the injection mold 112 is cooled by the injection mold 112, thereby forming the first preform 20. In the injection molding process S1, the first preform 20 can be demolded from the injection mold 112 at a high temperature. Specifically, during the injection molding of the first preform 20, during the cooling process after the filling process (including the holding pressure process), the cooling time is set to less than 1 / 2 of the filling time, preferably less than 1 / 3 of the filling time, and more preferably 0 seconds, and the first preform 20 is demolded from the injection mold 112 while the latent heat is high. After being demolded from the injection mold 112, the first preform 20 is conveyed to the temperature control unit 120 while being held in the neck mold 151.

[0054] like Figure 6 and Figure 7 As shown in the example, the temperature control step S2 includes deforming the first preform 20 into the second preform 30 and adjusting the temperature to a temperature suitable for blow molding. The temperature control step S2 also includes forming the second preform 30 by stretching the first preform 20 so that it contacts the inner wall surface 121a of the temperature control cavity formed by the temperature control mold 121. In this embodiment, the temperature control step S2 includes the following steps (pre-blow molding step): the cooling rod 122 in contact with the main body 22 of the first preform 20 is displaced (lowered) and compressed air is ejected from the first vent 123a or the second vent 123b, thereby contacting the first preform 20 with the inner wall surface 121a of the temperature control cavity. Furthermore, the temperature adjustment step S2 of this embodiment includes the following step (cooling blow molding step): after forming the second preform 30, compressed air for cooling is introduced into the interior of the second preform 30 through the second vent 123b or the first vent 123a and exhausted from the first vent 123a or the second vent 123b, thereby cooling the second preform 30. It should be noted that the directions of the compressed air flow in the pre-blow molding step and the cooling blow molding step can also be set to be opposite to each other.

[0055] Specifically, the first preform 20 transported from the injection molding section 110 to the temperature control section 120 contacts the abutment portion 123 and is stretched by the downward displacement of the cooling rod 122. The stretching of the first preform 20 by the cooling rod 122 is sometimes referred to as pre-stretching. The downward displacement (descent) of the cooling rod 122 is performed until the first preform 20 is in a position near the lower end of the inner wall surface 121a of the temperature control cavity defined by the temperature control mold 121 (to the extent that it does not contact the inner wall surface 121a) (white arrow A). Through pre-stretching, the first preform 20 is greatly stretched in the longitudinal direction and deformed into a shape close to that of the second preform 30. When the first preform 20 extends to a position near the lower end of the inner wall surface 121a of the temperature control cavity, the cooling rod 122 stops shifting (descending). At this time, a gap is formed between the outer surface (bottom) of the lower side of the stretched first preform 20 and the inner wall surface 121a. The vicinity of the gate portion of the first preform 20 is cooled from the inside by contact with the abutment portion 123. Furthermore, the body portion 22 of the first preform 20 is cooled (cooled) because it dissipates heat and becomes thinner due to the preliminary stretching.

[0056] Next, compressed air is introduced from the first vent 123a formed on the abutment portion 123 of the cooling rod 122. At this time, the second vent 123b is in a closed state. As a result, the pre-stretched first preform 20 further expands, contacts the temperature control mold 121, and becomes the shape of the second preform 30 (pre-blow molding process). Afterwards, after the second vent 123b is opened, compressed air continues to flow, and the introduced compressed air passes through the outside of the cooling rod 122 and is discharged from the second vent 123b. Therefore, the outside of the second preform 30 is cooled by contact with the temperature control mold 121, and the inside of the second preform 30 is cooled by the continuous flow of compressed air (cooling blow molding process). Thus, in the temperature control process S2, cooling can be performed at a high speed while the first preform 20 is deformed into the shape of the second preform 30. The second preform 30 cooled to a temperature suitable for blow molding in the temperature control section 120 is conveyed to the blow molding section 130 while being held in the neck mold 151. It should be noted that the following method (cooling blow molding process) may also be performed: when the cooling rod 122 is lowered or after it is lowered (after pre-stretching), compressed air is introduced from the second air vent 123b while the first air vent 123a is closed, so that the first preform 20 contacts the temperature control mold 121 and becomes the shape of the second preform 30 (pre-blowing process), and then the first air vent 123a is opened to allow the compressed air to continue to flow from the first air vent 123a and be exhausted from the second air vent 123b, thereby cooling the second preform 30.

[0057] like Figure 8As shown in the example, the blow molding step S3 includes blow molding the second preform 30 to produce the resin container 10. The blow molding step S3 of the present embodiment also includes stretching the second preform 30 by displacing the stretch rod 132.

[0058] Specifically, the second preform 30 conveyed from the temperature control section 120 is accommodated in the blow molding mold 131, contacts the stretching rod 132, and is stretched downward. Afterwards, the second preform 30 is blow-molded by introducing blowing air (compressed air) from the neck 21 of the second preform 30 into the interior of the second preform 30 via the blow core 133. The second preform 30 is deformed into a shape corresponding to the inner wall surface of the blow molding cavity specified by the blow molding mold 131 by blow molding, and becomes a resin container 10. The manufactured resin container is conveyed to the removal section 140 while being held by the neck mold, and is taken out from the manufacturing device 100 in the container removal process S4. It should be noted that in order to improve the shaping property, the blowing air is set to a higher pressure than the compressed air used in the temperature control process S2.

[0059] The preform is designed to achieve the optimal shape, taking into account the size, shape, specifications, and stretching conditions of the resin container. Preforms with excessively high stretch ratios during blow molding may fail to achieve the desired shape and wall thickness distribution even after blow molding. Therefore, in the case of the container of this embodiment, the preform has conventionally been designed to have a substantially conical shape (e.g., the shape of the second preform).

[0060] In recent years, due to the demand for resource conservation of resin materials, there has been a demand to reduce the amount of resin required to manufacture resin containers. However, when the conical preform is made thinner, the width of the injection cavity becomes too small, making it difficult to fill it with molten resin. As a result, problems such as poor molding such as short shots and undesirable temperature distribution of the preform are likely to occur. Therefore, it is difficult to manufacture conical and thin-walled preforms by injection molding. In addition, because the latent heat of the manufactured preform is easily reduced, even if blow molding is performed, the preform cannot be fully stretched, especially in blow molding methods / blow molding devices based on the hot parison method, and sometimes the desired resin container cannot be obtained.

[0061] In the first preform 20 of the above structure, the angle θ formed between the central axis X of the neck 21 and the main body 22 (or the angle of the corner 222) is 80° to 100°. The main body 22 is thick enough to not interfere with injection molding and to ensure the latent heat required for blow molding. This flat first preform 20 has a thickness suitable for ensuring the latent heat required for injection molding and blow molding, while also reducing the resin volume of the entire preform. By deforming and blow-molding this first preform 20, a lightweight resin container 10 with fewer manufacturing defects such as poor appearance can be provided.

[0062] According to the manufacturing method and manufacturing device 100 of the resin container 10 described above, the first preform 20 is manufactured in such a manner that the angle formed by the central axis X of the neck 21 and the main body 22 (the angle of the corner 222) is 80° to 100°. Such a flat first preform 20 has the thickness required for injection molding, and also suppresses the resin amount (volume) of the first preform 20 as a whole. By manufacturing from such a first preform 20, a lightweight resin container 10 is provided. Since the first preform 20 does not become a shape suitable for the final manufactured resin container 10, even if only the first preform 20 is blow-molded, the stretch ratio becomes too high, and sometimes the resin container 10 cannot be well molded. According to the above structure, in the temperature adjustment step S2, the first preform 20 is stretched to become the second preform 30. Therefore, by manufacturing the resin container 10 from the second preform 30, the stretch ratio is reduced compared to when manufacturing the resin container 10 from the first preform 20, making it easier to manufacture the resin container 10 in a good manner. Thus, a method and apparatus 100 for manufacturing the resin container 10 are provided that achieve both lightweighting and suppression of manufacturing defects in the resin container 10.

[0063] The first preform 20 is manufactured so that the thickness of the main body 22 is 5 mm or less. The resin container 10 manufactured from such a preform is even lighter. Furthermore, the method and apparatus 100 for manufacturing the resin container 10 configured as described above enable excellent manufacturing of the resin container 10 using the lightweight preform.

[0064] According to the above-described method for manufacturing the resin container 10, in the injection molding step S1, the first preform 20 is demolded from the injection molding mold 112 at a high temperature. In order to shorten the cycle time for manufacturing the resin container 10, it is important to shorten the time of the injection molding step S1. By demolding the first preform 20 from the injection molding mold 112 at a high temperature, the cooling time of the molten resin in the injection molding step S1 is shortened, and the cycle time for manufacturing the resin container 10 is also shortened. In addition, by displacing the cooling rod 122 to bring the first preform 20 into contact with the temperature control chamber, the deformation from the first preform 20 to the second preform 30 can be performed with a simple structure.

[0065] According to the manufacturing method of the resin container 10 of the above structure, the temperature control step S2 includes introducing cooling air into the interior of the second preform 30 through the first vent 123a formed in the cooling rod 122. Therefore, in the temperature control step S2, compressed air can be introduced into the interior of the second preform 30 through the first vent 123a formed in the cooling rod 122. If the preform is slowly cooled in the temperature control step S2, it may sometimes cause poor appearance such as whitening. The outside of the second preform 30 is cooled by contact with the inner wall surface 121a of the temperature control chamber, and the inside of the second preform 30 is cooled by the introduction of compressed air and convection, so that the cooling rate of the second preform 30 is increased.

[0066] While the embodiments of the present disclosure have been described above, the technical scope of the present disclosure should not be construed in a limiting sense based on the description of these embodiments. These embodiments are merely examples, and those skilled in the art will appreciate that various modifications of these embodiments are possible within the scope of the invention as described in the claims. The technical scope of the present disclosure should be determined based on the scope of the invention as described in the claims and their equivalents.

[0067] For example, in this embodiment, the first preform 20 is described in which the angle θ formed between the central axis X of the neck 21 and the main body 22 is approximately 90°. However, the shape of the first preform 20 is not limited to the example of this embodiment, and the angle θ formed between the central axis X of the neck 21 and the main body 22 can be appropriately selected within the range of 80° to 100°. For example, when the angle θ formed between the central axis X of the neck 21 and the main body 22 is 100°, the main body 22 of the first preform 20 has a shape that protrudes downward from the lower end of the neck 21. When the angle θ formed between the central axis X of the neck 21 and the main body 22 is 80°, the main body 22 of the first preform 20 has a shape that protrudes upward from the lower end of the neck 21.

[0068] The thickness of the main body 22 of the first preform 20 may be non-uniform. For example, the thickness of the main body 22 near the neck 21 may be greater than the thickness near the center of the main body 22. This facilitates securing latent heat in the main body near the neck 21, which is particularly susceptible to cooling in the first preform 20.

[0069] This application is based on Japanese patent application No. 2022-204775 filed on December 12, 2022, the contents of which are incorporated herein by reference.

[0070] Description of Reference Numerals

[0071] 10: Resin container;

[0072] 11: container head;

[0073] 12: container body;

[0074] 13: bottom of container;

[0075] 20: first preform;

[0076] 21: Neck;

[0077] 22: Main body;

[0078] 30: second preform;

[0079] 100: Manufacturing device;

[0080] 110: injection molding department;

[0081] 111: injection molding device;

[0082] 112: Injection molding mold;

[0083] 113: injection molding core;

[0084] 114: injection cavity mold;

[0085] 120: Temperature control unit;

[0086] 121: Temperature control mold;

[0087] 121a: Inner wall surface;

[0088] 122: cooling rod;

[0089] 123: Butt;

[0090] 123a: first vent;

[0091] 123b: second vent;

[0092] 130: blow molding department;

[0093] 131: Blow molding mold;

[0094] 132: stretching rod;

[0095] 140: extraction part;

[0096] 150: conveying unit;

[0097] 151: Neck mold;

[0098] 211: flange portion;

[0099] 221: lateral face;

[0100] 222: Corner;

[0101] 223: plate-shaped part;

[0102] X: center axis;

[0103] S1: injection molding process;

[0104] S2: temperature adjustment process;

[0105] S3: blow molding process;

[0106] S4: Container removal process.

Claims

1. A preform for manufacturing a resin container having a container head, a container body and a container bottom, wherein: The preform includes an annular neck portion constituting the container head portion and a main body portion constituting the container main body portion and the container bottom portion. The angle formed by the central axis of the neck and the main body is 80° to 100°.

2. The preform according to claim 1, wherein The thickness of the main body is less than 5 mm.

3. A method for manufacturing a resin container comprising a container head, a container body, and a container bottom, comprising: Injection molding process, injecting molten resin into the injection cavity formed by the injection molding mold to form a first preform; a temperature adjustment step of transforming the first preform into a second preform and adjusting the temperature to a temperature suitable for blow molding; and a blow molding step of blow-molding the second preform to produce a resin container; The temperature adjustment process includes: stretching the first preform so that it contacts the inner wall surface of the temperature control cavity formed by the temperature control mold, thereby forming the second preform; In the first preform, The container comprises an annular neck portion constituting the container head portion and a main body portion constituting the container main body portion and the container bottom portion. The angle formed by the central axis of the neck and the main body is 80° to 100°.

4. The method for manufacturing a resin container according to claim 3, wherein: The thickness of the main body portion of the first preform is 5 mm or less.

5. The method for manufacturing a resin container according to claim 3 or 4, wherein: In the injection molding process, the first preform is demoulded from the injection molding mold at a high temperature. The temperature adjustment step includes displacing a cooling rod in contact with the main body of the first preform and ejecting compressed air from an air vent formed in the cooling rod, thereby bringing the first preform into contact with the inner wall surface of the temperature adjustment chamber.

6. The method for manufacturing a resin container according to claim 5, wherein: The temperature adjustment step includes introducing cooling air into the interior of the second preform through the vent after forming the second preform.

7. A manufacturing apparatus for a resin container comprising a container head, a container body, and a container bottom, comprising: An injection molding unit including an injection molding die, wherein the injection molding die forms an injection cavity for manufacturing a first preform; a temperature regulating portion including a deformation portion for deforming the first preform into a second preform and a temperature regulating mold constituting a temperature regulating chamber; and The blow molding section includes a blow molding die that defines the shape of the resin container manufactured by blow molding the second preform. The inner wall surface of the temperature control chamber is configured to cool the first preform by contacting the first preform and to define the shape of the second preform. The inner wall surface of the injection cavity is composed of: In the first preform, an annular neck portion constituting the container head portion and a main body portion constituting the container main body portion and the container bottom portion are defined. The angle formed by the central axis of the neck and the main body is 80° to 100°.

8. The manufacturing apparatus for a resin container according to claim 7, wherein: The injection cavity is configured so that the thickness of the main body of the first preform is 5 mm or less.

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