Method for manufacturing resin wide-mouth container, manufacturing apparatus, and resin wide-mouth container

Abstract

The present invention relates to a method for manufacturing a resin wide-mouth container, at least comprising: an injection molding step for injection molding a bottomed preform (30) made of resin; and a blow molding step for manufacturing a resin wide-mouth container by blow molding the injection-molded preform (30). In the injection molding step, the preform (30) is injection molded so that an outwardly projecting protrusion (38) is formed on an outer peripheral portion of a first lip portion (36) closer to a first body portion (34) than a flange portion (37), and the preform (30) is separated from an injection molding mold when the first lip portion (36) provided with the protrusion (38) is held by a lip mold (20) having a recess engaging with the protrusion (38).

Description

Technical Field

[0001] This invention relates to a method and apparatus for manufacturing resin wide-mouth containers, and to resin wide-mouth containers. Background Technology

[0002] Patent Document 1 discloses a cup-shaped polyester container formed from sheet material. Patent Document 2 discloses a wide-mouth plastic container manufactured by a cold preform biaxial stretch blow molding process. Patent Document 3 discloses a packaging cup-shaped container formed by stretching and blow molding polyethylene terephthalate (PET).

[0003] Citation List

[0004] Patent documents

[0005] Patent Document 1: JP2004-115064A

[0006] Patent Document 2: JP2004-010061A

[0007] Patent Document 3: JP2004-352332A Summary of the Invention

[0008] Technical issues

[0009] In methods of forming wide-mouth containers from sheet metal, the cost of sheet metal is generally high, and post-processing (such as trimming) is required after vacuum forming or compression molding. Furthermore, in sheet metal forming methods, the container itself is likely to be scratched, making it difficult to produce wide-mouth containers with excellent appearance. In contrast, while some friction scratches may occur on the outer surface in methods of forming wide-mouth containers using cold preform biaxial stretch blow molding, it is possible to produce wide-mouth containers with a superior appearance compared to the methods described above. However, the cost is increased.

[0010] On the other hand, in the hot preform stretch blow molding (ISBM) method, the injection molding and stretch blow molding of the container preform can be performed in a single manufacturing step. If manufacturing time can be shortened in the ISBM method, containers with excellent appearance can be provided while reducing costs. As disclosed in WO2019 / 078358, there is a method for demolding the preform at high temperature during the injection molding step as a means of shortening manufacturing time in the ISBM method. However, it has been found that in the case of manufacturing wide-mouth containers by the ISBM method, during the injection molding step, when the preform is demolded from the injection cavity mold or injection core mold, it is likely to detach from the neck mold.

[0011] One object of the present invention is to provide a manufacturing method and manufacturing apparatus for manufacturing resin wide-mouth containers that can advantageously manufacture wide-mouth containers, as well as a novel resin wide-mouth container.

[0012] Problem Solution

[0013] According to one aspect of the present invention, a method for manufacturing a resin wide-mouth container is a hot preform manufacturing method for manufacturing a resin wide-mouth container, comprising at least: an injection molding step: injection molding a resin bottomed preform, the resin bottomed preform including a first bottom, a first body portion connected to the first bottom, and a first lip having a cylindrical wide mouth connected to the first body portion on the opposite side of the first bottom, the first lip including a flange portion disposed at an edge located on the opposite side of the first body portion and projecting outward; and a blow molding step: blow molding the injection-molded preform to form a resin wide-mouth container, wherein, in the injection molding step, molten resin is injected into a space in the shape of the preform to injection mold the preform, the space being formed by a closed injection core mold, an injection cavity mold, and a lip mold, such that an outwardly projecting protrusion is formed on the outer periphery of the first lip portion closer to the first body portion than the flange portion, and the first lip including the protrusion is held by the lip mold including a recess to demold the preform from the injection molding mold, the recess being configured to engage with the protrusion.

[0014] According to one aspect of the present invention, a manufacturing apparatus for manufacturing resin wide-mouth containers is a hot-form preform manufacturing apparatus for manufacturing resin wide-mouth containers. The apparatus includes at least: an injection molding section configured to injection mold a resin preform with a bottom, the preform including a first bottom, a first body portion connected to the first bottom, and a first lip having a cylindrical wide mouth connected to the first body portion on the side opposite to the first bottom, the first lip including a flange portion disposed at an edge located on the side opposite to the first body portion and projecting outwards; and a blow molding section configured to blow mold the injection-molded preform. The preform is used to manufacture a resin wide-mouth container, wherein the injection molding section is configured to inject molten resin into a space in the shape of the preform to injection mold the preform, the space being formed by a clamping injection core mold, an injection cavity mold, and a lip mold, wherein the lip mold includes a lip peripheral defining portion, the lip peripheral defining portion being configured to define the outer periphery of a first lip of the preform other than the flange portion, and wherein the lip peripheral defining portion includes a recess, the recess being configured to be a protrusion oriented outwardly at the upper limit of the outer periphery of the first lip portion closer to the first body portion than the flange portion.

[0015] According to one aspect of the present invention, a resin wide-mouth container is a resin wide-mouth container comprising: a bottom; a body portion connected to the bottom; and a lip portion having a cylindrical wide mouth connected to the body portion on the side opposite to the bottom, wherein the lip portion includes a flange portion disposed at an edge located on the side opposite to the bottom and projecting outward, and a protrusion portion disposed on an outer periphery of the lip portion closer to the body portion than the flange portion and projecting outward, and wherein the outer diameter of the lip portion is the maximum diameter of the wide-mouth container.

[0016] Beneficial effects of the present invention

[0017] According to the present invention, a manufacturing method and manufacturing apparatus for manufacturing resin wide-mouth containers, as well as novel resin wide-mouth containers, can be provided that are capable of advantageously manufacturing wide-mouth containers. Attached Figure Description

[0018] Figure 1 This is a schematic diagram illustrating a manufacturing apparatus for producing resin wide-mouth containers according to one embodiment.

[0019] Figure 2A This is a view showing the lip mold set up in a manufacturing apparatus for manufacturing resin wide-mouth containers according to this embodiment.

[0020] Figure 2B yes Figure 2A A magnified view of a portion of region B shown.

[0021] Figure 3 This is a view showing a preform of a resin wide-mouth container according to this embodiment.

[0022] Figure 4 This is a view showing the injection molding section of a manufacturing apparatus for manufacturing resin wide-mouth containers according to this embodiment.

[0023] Figure 5 This is a view showing the temperature control unit according to this embodiment.

[0024] Figure 6 This is a view showing the blow molding section according to this embodiment.

[0025] Figure 7 This is a view showing a resin wide-mouth container according to this embodiment. Detailed Implementation

[0026] An embodiment of the present invention will be described below with reference to the accompanying drawings. It should be noted that, for ease of description, the dimensions of each component shown in the drawings may differ from the dimensions of each actual component.

[0027] First, it will be combined with the appendix Figure 1Describes manufacturing equipment 10 for manufacturing resin wide-mouth containers. Figure 1 This is a functional block diagram of manufacturing equipment 10.

[0028] like Figure 1 As shown, the manufacturing equipment 10 is a hot preform type equipment, including an injection molding unit 11 for manufacturing resin wide-mouth container preforms, a temperature regulating unit 12 for adjusting the temperature of the manufactured preforms, a blow molding unit (an example of a blow molding apparatus) 13 for blow molding the preforms to manufacture containers, and an extraction unit 14 for removing the manufactured containers. An injection device 15, configured to supply resin material as raw material, is connected to the injection molding unit 11.

[0029] The injection molding section 11, temperature regulating section 12, blow molding section 13, and take-out section 14 are positioned at a predetermined angle (90 degrees in this embodiment) around the conveying device 16. The conveying device 16 includes a rotating plate or similar component. The conveying device 16 is configured to... Figure 2A and Figure 2B The lip mold 20, attached to the conveying device 16, supports the preform or wide-mouth container (which will be described later) and conveys the preform or wide-mouth container to each part as the rotating plate rotates.

[0030] Here, we will combine Figure 2A and Figure 2B To describe the lip mold 20. Figure 2A This is a sectional view obtained by cutting the lip mold 20 with a plane along the central axis A of the lip mold 20. Figure 2B yes Figure 2A A magnified view of a portion of region B. The lip mold 20 is configured to allow for the opening and closing operations of the two joining molds 20a and 20b (e.g., in...). Figure 2A The lip mold 20 is used to support or release the preform or wide-mouth container by moving it left and right in the middle. With the two joining molds 20a and 20b closed, the lip mold 20 has a generally cylindrical shape. The lip mold 20 has a retaining portion 22 configured to hold the lip of the preform or wide-mouth container in the closed state.

[0031] This will combine Figure 3 To describe the preform 30 formed by the manufacturing equipment 10 of this embodiment. Figure 3This is a cross-sectional view obtained by cutting the preform 30 with a plane along the central axis C of the preform 30. The preform 30 is a resin molded product, including a first bottom 32, a first body portion 34 connected to the first bottom 32, and a first lip 36 having a cylindrical wide opening connected to the first body portion 34 on the opposite side of the first bottom 32. The diameter D of the first lip 36 can be, for example, 65 mm or more and 110 mm or less, preferably 80 mm or more and 95 mm or less. The first lip 36 is the portion held by the holding portion 22 of the lip mold 20 (see...). Figure 2A The length L1 of the first lip 36 in the direction of the central axis C can be, for example, 8.0 mm or more and 15 mm or less. The length L2 of the first lip 36 that maintains contact with the lip mold 20 in the direction of the central axis C is shorter, and can be, for example, 4.0 mm or more and 7.0 mm or less, or about 5 mm (4.5 mm or more and 5.5 mm or less). Furthermore, the shapes of the first lip 36 and the first body portion 34 are both circular in the top view or horizontal cross-section. In addition, the length L of the preform 30 in the direction of the central axis C can be, for example, 30 mm or more and 60 mm or less, and can be shorter than the diameter D of the first lip.

[0032] The first lip 36 has an annular flange 37, which is located at the edge opposite to the first body portion 34 and protrudes outward. The preform 30 has an annular protrusion 38, which is located on the outer periphery of the first lip 36 closer to the first body portion 34 than the flange 37 and protrudes outward. The flange 37 and the protrusion 38 are formed along the circumferential direction of the first lip. The outward protrusion length of the flange 37 may be shorter than the length of the first lip 36 in the direction of the central axis C. The outward protrusion length L3 of the flange 37 may be, for example, 1.0 mm or more and 3.0 mm or less, more preferably 1.5 mm or more and 2.5 mm or less. The outward protrusion length of the protrusion 38 may be shorter than the outward protrusion length of the flange 37. The outward protrusion length L4 of the protrusion 38 may be, for example, 0.3 mm or more and 1.5 mm or less, more preferably 0.4 mm or more and 0.6 mm or less.

[0033] The thickness Th1 of the first bottom portion 32 can be 1.5 mm or more and 2.0 mm or less. The ratio Th2 / Th1 of the thickness Th2 of the first body portion 34 (the maximum thickness of the first body portion 34) to the thickness Th1 of the first bottom portion 32 can be 0.8 or more and 1.4 or less, more preferably 0.95 or more and 1.25 or less. In the cross-section of the preform 30 obtained by cutting the preform 30 with a plane along the central axis C of the first lip portion 36 ( Figure 3The inclination angle θ of the first body part 34 relative to the central axis C can be 20° or more and 70° or less, or 30° or more and 50° or less. The cross-sectional shape of the preform can be approximately triangular or approximately trapezoidal.

[0034] Here, back to Figure 2A and Figure 2B The lip mold 20 is described again. The retaining portion 22 of the lip mold 20 has a lip peripheral defining portion 24, which is configured to define the outer periphery of the preform 30, excluding the flange portion 37 of the first lip 36, when the preform 30 is molded in the injection molding portion 11. The lip peripheral defining portion 24 has a recess 26, which is configured to define the protrusion 38 of the preform 30 when the preform 30 is molded in the injection molding portion 11.

[0035] Subsequently, combined Figure 4 Let's describe the injection molding section 11. Figure 4 This is a schematic cross-sectional view showing one aspect of the injection molding section 11. The injection molding section 11 includes an injection molding die comprising an injection core die 114 and an injection cavity die 112. The injection molding section 11 is configured to inject a synthetic resin material, such as a polyester-based resin (e.g., PET: polyethylene terephthalate), into a space in the shape of a preform 30 via a runner 116 and a gate 118 to injection mold the preform 30, wherein the space is formed by the clamping injection core die 114, the injection cavity die 112, and the lip die 20. For example, a cooling medium of 5°C to 20°C flows within the injection core die 114 and the injection cavity die 112 to keep these molds at a low temperature during molding.

[0036] Here, combined Figure 5 To describe Figure 1 The temperature control unit 12 shown. Figure 5 This is a schematic cross-sectional view showing one aspect of the temperature regulation unit 12. The temperature regulation unit 12 includes a mold unit for performing temperature-regulated blow molding (cooled blow molding), the mold unit including a cavity mold (cavity mold for temperature regulation) 122 configured to receive the preform 30 and an air introduction member 124 configured to contact the preform 30 in an airtight manner and deliver air into the preform 30.

[0037] The cavity mold 122 has a fixed (single-unit) structure, which is configured to define a space with a shape substantially the same as that of the preform 30 made by the injection molding section 11. For example, a temperature regulating medium (cooling medium) at 20°C to 100°C (more preferably 60°C to 90°C) flows within the cavity mold 122 to maintain a low temperature.

[0038] The air inlet member 124 includes a hollow rod member 124a and an assembly core (a blow-molded core member for temperature regulation) 124b, the rod member including an air passage hole disposed therein. The rod member 124a is housed in the assembly core 124b to be movable vertically. An internal vent 126a is provided at the end of the rod member 124a through which air can be exhausted or drawn in. The air temperature is appropriately set corresponding to the thickness of the preform 30 or the wide-mouth container 40. The assembly core 124b is configured to assemble (tightly contact) with the first lip 36 when the air inlet member 124 is inserted (airtightly contacted) into the preform 30. This prevents air in the preform 30 from leaking from the first lip 36 to the outside of the assembly core 124b. The gap between the rod member 124a and the assembly core 124b is an air passage for supplying / exhausting air relative to the preform 30. The gap formed by the end of the assembly core 124b and the rod member 124a constitutes an external vent 126b, through which air can be exhausted or drawn in. The internal vent 126a and the external vent 126b can be used as an air blowing port and an air exhaust port, respectively.

[0039] It should be noted that, instead of or in combination with the above methods, the temperature regulating unit 12 can be a method in which the preform is clamped using a temperature regulating cavity mold and a temperature regulating core mold (temperature regulating rod mold), as well as a temperature regulating device such as various types of infrared heaters, RED types, electromagnetic wave heating types, etc. It should also be noted that the temperature regulating unit 12 can be omitted. For example, the thickness distribution of a wide-mouth container can be improved by employing the temperature regulating unit 12. However, from a manufacturing efficiency perspective, it is preferable to employ a method in which, while the preform is in contact with the aforementioned temperature regulating cavity mold, air is introduced into the preform to simultaneously cool both the interior and exterior of the preform. Furthermore, when employing this method, it is preferable that the cooling intensity of the external temperature regulating cavity mold is higher than the cooling intensity of the internal air.

[0040] Here, combined Figure 6 To describe Figure 1 The temperature control unit 12 shown. Figure 6 This is a schematic cross-sectional view showing one aspect of the blow molding section 13. The blow molding section 13 includes a tension bar 132, a blow core mold 134, a blow cavity mold 136, and a blow bottom mold 138. The blow molding section 13 is configured to introduce air from the blow core mold 134 to inflate the preform 30 into the shape defined by the blow cavity mold 136 and the blow bottom mold 138, and to form a wide-mouth container while stretching the injection-molded preform 30 using, for example, the tension bar 132.

[0041] Subsequently, combined Figure 7 This describes the wide-mouth container 40 formed by the manufacturing equipment 10 of this embodiment. Figure 7This is a side view of the wide-mouth container 40. The wide-mouth container 40 is a cup-shaped container, including a second bottom 42, a second body portion 44 connected to the second bottom 42, and a second lip (opening) 46 with a cylindrical wide mouth connected to the second body portion 44 on the opposite side of the second bottom 42. The second lip 46 includes an annular flange portion 47 located at the edge opposite to the second body portion 44 and protruding outward, and an annular protrusion 48 located on the outer periphery of the second lip 46 closer to the second body portion 44 than the flange portion 47 and protruding outward. The outer diameter of the flange portion 47 of the second lip 46 is the maximum diameter of the wide-mouth container 40. The vertical draw ratio (SVR) of the wide-mouth container 40 to the preform 30 can be greater than or equal to 4.0 and less than or equal to 6.0. The diameter of the second lip 46 of the wide-mouth container 40, as well as the dimensions and shapes of the flange 47 and the protrusion 48, are the same as those of the first lip 36 of the preform 30. By stretching the first lip 36 of the preform 30 during the blow molding step, the length L1' of the second lip 46 of the wide-mouth container 40 can be greater than the length L1 of the first lip 36. A parting line of the lip mold 20 is formed on the second lip 46. More specifically, two vertical parting lines extending in the vertical direction are formed on the first lip 36 and the second lip 46, serving as traces of the contact surfaces of the assembly molds 20a and 20b constituting the lip mold 20, and one annular parting line extending in the circumferential direction is formed on the traces of the contact surfaces of the lip mold 20 and the injection cavity mold 112. These parting lines are formed within the area of ​​the holding portion 22 of the lip mold 20 (within the length L2 of the first lip 36 of the preform 30). In addition, injection marks (with a circular cross-section) of molten resin discharged from gate 118 are formed on the central region of the lower surface of the second bottom 42.

[0042] Next, a manufacturing method for manufacturing a wide-mouth container according to this embodiment will be described. This manufacturing method is a hot preform method, including an injection molding step of injection molding a preform 30, a temperature conditioning step of adjusting the temperature of the injection-molded preform 30 to a temperature suitable for blow molding, and a blow molding step of blow molding the preform 30 to form a wide-mouth container 40.

[0043] Combination Figure 4 The injection molding step is described below. In the injection molding step, molten resin is injected through runner 116 and gate 118 into the space forming the shape of the preform 30, which is created by the mold core mold 114, injection cavity mold 112, and lip mold 20. After a predetermined time has elapsed, the injection core mold 114 and lip mold 20 are pulled up to demold the preform 30 from the injection cavity mold 112. At this time, the protrusion 38 of the preform 30 engages with the recess 26 of the lip mold 20 (see [link to documentation]). Figure 2BFurthermore, the retaining portion 22 of the lip mold 20 holds the flange portion 37 of the preform 30. In this state, the first lip 36 is held by the lip mold 20, and the preform 30 is demolded from the injection cavity mold 112. Here, when the time from the completion of molten resin injection to the demolding of the preform 30 is shortened, the preform 30 is demolded at a high temperature. When the preform 30 is demolded from the injection mold at a high temperature, the cooling time from the completion of molten resin injection in the injection mold to the demolding of the preform 30 can be set to, for example, 0.0 to 1.5 seconds. It should be noted that the above-mentioned "injection of molten resin" refers to the resin filling step including the pressure holding step. The time of the resin filling step can be set to, for example, 2.5 to 4.5 seconds. Furthermore, the predetermined time for conveying the demolded preform 30 to the temperature conditioning step can be set to, for example, 2.0 to 6.0 seconds. During this time, for example, when the preform 30 is demolded from the injection molding mold at a high temperature, the outer surface temperature of the preform 30 rises rapidly after demolding and becomes approximately above 110°C and below 140°C.

[0044] In the temperature adjustment step, in the above-mentioned temperature adjustment unit 12 ( Figure 5 In the blow molding process, the temperature of the preform 30 formed in the injection molding step is adjusted to a temperature suitable for blow molding. First, the preform 30 is housed in the space of the cavity mold 122 with the shape of the preform. Next, an air-introducing component 124 is inserted (airtightly contacted) into the preform 30 housed in the cavity mold 122. Subsequently, a cooling blow molding operation is performed by opening the internal vent 126a to introduce air from the internal vent 126a and discharging the air to the outside of the preform 30 through the external vent 126b. At this time, since air is continuously ejected from the internal vent 126a, the preform 30 is cooled from the inside by the convection of the air flowing in the preform 30. In addition, since the preform 30 is in continuous contact with the cavity mold 122, the preform is also cooled from the outside, thereby regulating its temperature and reducing temperature unevenness caused during the injection molding process.

[0045] It should be noted that although the temperature conditioning step can be omitted, the thickness distribution of the wide-mouth container can be improved, for example, by using the temperature conditioning unit 12. Furthermore, when the preform 30 is demolded at high temperature during the injection molding step, the preform 30 can be cooled to a predetermined temperature using cooling air or the like during the temperature conditioning step. For example, the outer surface temperature of the preform 30 can be reduced by approximately 30°C to 50°C from the time the preform is transported to the temperature conditioning unit 12. By demolding the preform 30 at high temperature during the injection molding step and cooling the preform in the temperature conditioning step, a wide-mouth container 40 with an excellent appearance can be formed while shortening the cycle time. Furthermore, during the temperature conditioning step, a cooling rod configured to contact the inner surface of the first bottom 32 of the preform 30 can be provided at the end of the rod member 124a.

[0046] In the blow molding step, the preform 30 is housed in a cavity defined by a blow molding cavity mold 136 and a blow molding bottom mold 138 corresponding to the shape of the wide-mouth container 40 (see [link]). Figure 7 The preform 30 is then expanded by introducing blow molding air from the blow molding core mold 134, while optionally stretching the preform by the stretching rod 132 to form a wide-mouth container 40. Figure 6 Then, the wide-mouth container 40 is released from the mold of the blow-molded part 13, and the wide-mouth container 40 is conveyed to the take-out part 14 and taken out. Through the above process, the wide-mouth container 40 is manufactured. It should be noted that the wide-mouth container that can be manufactured in the manufacturing method of this embodiment is not limited to... Figure 7 The specific wide-mouth container 40 shown.

[0047] In this embodiment, the first lip 36 of the preform 30 and the second lip 46 of the wide-mouth container 40 correspond to each other, and these lips are shorter in length in the direction of the central axis C of the preform 30. Therefore, when the preform and the wide-mouth container are demolded from the mold in the injection molding step, the preform and the wide-mouth container are likely to detach from the lip mold 20.

[0048] In the hot preform manufacturing method described in this embodiment, which includes injection molding and blow molding steps, the preform 30 is injection molded such that the first lip 36 of the preform 30 includes a protrusion 38, and when the preform 30 is pulled out from the injection cavity mold 112, the protrusion 38 of the preform 30 engages with the recess 26 of the lip mold 20, thereby preventing the preform 30 from detaching. Figure 2B and Figure 4 Thus, wide-mouth containers 40 can be appropriately manufactured.

[0049] Furthermore, the wide-mouth container 40 described in this embodiment has a relatively large vertical stretch relative to the preform 30, which may cause the thickness distribution of the body portion in the vertical direction to become uneven. Additionally, during the injection molding process of the second bottom 42 of the wide-mouth container 40, a whitening (crystallization) phenomenon may occur in the area surrounding the gate.

[0050] In the hot preform manufacturing method (wherein the preform 30 is demolded at high temperature during the injection molding step) (including the injection molding step, temperature conditioning step, and blow molding step described in this embodiment), the preform 30 is injection molded such that the thickness Th1 of the first bottom 32 in the cross-section of the preform 30 obtained by cutting the preform 30 along a plane along the central axis C of the first lip 36 becomes 1.5 mm or more, or the ratio of the thickness Th1 of the first bottom 32 to the thickness Th2 of the first body portion 34 becomes 0.8 or more (see...). Figure 3 Furthermore, the inclination angle of the first body portion 34 relative to the central axis C is 20° or more and 70° or less (see [reference]). Figure 3 The container is cooled during the temperature conditioning step. This improves the thickness distribution of the wide-mouth container 40 in the vertical direction produced by the high-speed ISBM process. Furthermore, it appropriately reduces the whitening phenomenon of the wide-mouth container 40 around the gate 118 of the molten resin during the injection molding step, and produces a wide-mouth container with a superior appearance (see [link to article]). Figure 4 Furthermore, the formability (transferability) of the second bottom 42 of the wide-mouth container 40 has also been improved.

[0051] In fact, according to the inventors' assessment, when the thickness Th1 of the first bottom 32 of the preform 30 is 1.4 mm and the thickness Th2 of the first body 34 is 2.0 mm, the wide-mouth container 40 exhibits a slight whitening phenomenon around the gate. On the other hand, when the thickness Th1 of the first bottom 32 of the preform 30 is 1.8 mm and the thickness Th2 of the first body 34 is 2.0 mm, the wide-mouth container 40 shows almost no whitening phenomenon around the gate, and high transparency is observed. The inventors believe that the reason for the above results is that the increased distance between the bottom of the gate 118 and the injection core mold 114 reduces the resin resistance when the molten resin flows in, and also reduces the generation of shear heat, while suppressing the first bottom 32 of the molded preform 30 from being in an abnormally high temperature state. Therefore, whitening (crystallization) caused by the slow cooling of the first bottom 32 is reduced. Furthermore, the inventors believe that the first body portion 34 of the preform 30 is thicker than that of related technologies, which ensures sufficient residual heat even after cooling through the temperature conditioning step of the high-speed ISBM method before blow molding. This is believed to effectively improve the thickness uniformity of the second body portion 44 of the wide-mouth container 40.

[0052] Furthermore, in the molding of the wide-mouth container 40 described in this embodiment, the inner and outer surfaces of the wide-mouth container 40 can have different surface roughnesses by roughening the cavity surface of the temperature regulating cavity mold or the blow molding cavity mold. Therefore, when the wide-mouth containers 40 are overlapped or separated, the resistance between the wide-mouth containers 40 can be reduced, and operability can be improved.

[0053] It should be noted that the present invention is not limited to the above embodiments, and the present invention can be freely modified and improved as appropriate. Furthermore, as long as the present invention can be implemented, the material, shape, size, value, form, quantity, and placement of each element in the above embodiments can be arbitrary and without particular limitation.

[0054] The following section lists aspects extracted from the above embodiments and their modifications.

[0055] [1] A hot preform manufacturing method for manufacturing a resin wide-mouth container, the manufacturing method comprising at least: an injection molding step: injection molding a resin bottomed preform, the resin bottomed preform including a first bottom, a first body portion connected to the first bottom, and a first lip having a cylindrical wide mouth connected to the first body portion on the opposite side of the first bottom, the first lip including a flange portion disposed at an edge located on the opposite side of the first body portion and projecting outward; and a blow molding step: blow molding the injection-molded preform to form a resin wide-mouth container, wherein, in the injection molding step, molten resin is injected into a space of the preform shape to injection mold the preform, the space being formed by a molded injection core mold, an injection cavity mold and a lip mold, such that an outwardly projecting protrusion is formed on the outer periphery of the first lip portion closer to the first body portion than the flange portion, and the first lip including the protrusion is held by a lip mold including a recess to demold the preform from the injection molding mold, the recess being configured to engage with the protrusion.

[0056] [2] The manufacturing method according to [1] further includes: a temperature adjustment step: between the injection molding step and the blow molding step, adjusting the temperature of the injection-molded preform to a temperature suitable for blow molding, wherein, in the injection molding step, the injection-molded preform is injection-molded such that the thickness of the first bottom becomes 1.5 mm or more or the ratio of the thickness of the first bottom to the thickness of the first body portion becomes 0.8 or more, and the injection-molded preform is injection-molded such that the angle of inclination of the first body portion relative to the central axis in the cross section of the preform obtained by cutting the preform along a plane along the central axis of the first lip becomes 20° or more and 70° or less, and wherein, in the injection molding step, the preform is demolded at a high temperature, in the temperature adjustment step, the preform is cooled to a temperature suitable for blow molding, and in the blow molding step, a resin wide-mouth container is formed by stretch blow molding.

[0057] [3] According to the manufacturing method described in [1] or [2], in the blow molding step, a resin wide-mouth container is manufactured, the resin wide-mouth container including a second bottom, a second body portion connected to the second bottom, and a second lip portion having a cylindrical wide mouth connected to the second body portion on the opposite side of the second bottom.

[0058] [4] A hot preform manufacturing apparatus for manufacturing resin wide-mouth containers, the apparatus comprising at least: an injection molding section configured to injection mold a resin bottomed preform, the resin bottomed preform including a first bottom, a first body portion connected to the first bottom, and a first lip having a cylindrical wide mouth connected to the first body portion on the opposite side of the first bottom, the first lip including a flange portion disposed at an edge located on the opposite side of the first body portion and protruding outward; and a blow molding section configured to blow mold the injection-molded preform, to A resin wide-mouth container is manufactured, wherein the injection molding part is configured to inject molten resin into a space of a preform shape to injection mold the preform. The space is formed by a molded injection core mold, an injection cavity mold, and a lip mold. The lip mold includes a lip peripheral defining portion, which is configured to define the outer periphery of a first lip of the preform, excluding the flange portion. The lip peripheral defining portion includes a recess, which is configured to be a protrusion that extends outward at the upper limit of the outer periphery of the first lip, which is closer to the first body portion than the flange portion.

[0059] [5] A resin wide-mouth container includes: a bottom; a body portion connected to the bottom; and a lip portion having a cylindrical wide mouth connected to the body portion on the side opposite to the bottom, wherein the lip portion includes a flange portion disposed at an edge located on the side opposite to the bottom and projecting outward, and a protrusion portion disposed on the outer periphery of the lip portion closer to the body portion than the flange portion and projecting outward, and wherein the outer diameter of the lip portion is the maximum diameter of the wide-mouth container.

[0060] This application is based on Japanese Patent Application No. 2020-078536, filed on April 27, 2020, the entire contents of which are incorporated herein by reference. Furthermore, the entire contents of all references cited herein are also incorporated herein.

[0061] List of reference numerals

[0062] 10: Manufacturing equipment; 11: Injection molding unit; 12: Temperature control unit; 13: Blow molding unit; 14: Take-out unit; 15: Injection device; 16: Conveying device; 20: Lip mold; 22: Holding part; 24: Lip periphery limiting part; 26: Recess; 30: Preform; 31: Gate mark; 32: First bottom; 34: First body part; 36: First lip; 37: Flange part; 38: Protrusion part; 40: Wide-mouth container; 4 2: Second bottom, 44: Second body, 46: Second lip, 112: Injection cavity mold, 114: Injection core mold, 116: Runner, 118: Gate, 122: Cavity mold, 124: Air inlet component, 124a: Rod component, 124b: Assembly core, 126a: Internal vent, 126b: External vent, 132: Tension rod, 134: Blow molding core mold, 136: Blow molding cavity mold, 138: Blow molding bottom mold

Claims

1. A method for manufacturing a hot-form preform for resin wide-mouth containers, comprising at least: Injection molding step: Injection molding resin base preform, the preform includes a first bottom, a first body portion connected to the first bottom, and a first lip portion having a cylindrical wide mouth connected to the first body portion on the opposite side of the first bottom, the first lip portion including a flange portion disposed at an edge located on the opposite side of the first body portion and protruding outward. as well as Blow molding step: Blow molding the injection-molded preform to produce a resin wide-mouth container. In the injection molding step, Molten resin is injected into the space of the preform shape to injection mold the preform. The space is formed by a molded injection core mold, an injection cavity mold, and a lip mold, such that an outwardly protruding protrusion is formed on the outer periphery of the first lip, which is closer to the first body portion than the flange portion. The first lip, including the protrusion, is held by the lip mold, including a recess, to demold the preform from the injection molding mold, the recess being configured to engage the protrusion. In the injection molding step, the preform is injection molded such that the outward protrusion of the protrusion is shorter than the outward protrusion of the flange. While holding the retaining part of the lip mold in place of the flange and engaging the recess of the lip mold with the protrusion, the preform is held and demolded.

2. The manufacturing method according to claim 1, further comprising: Temperature control step: Between the injection molding step and the blow molding step, the temperature of the injection-molded preform is adjusted to a temperature suitable for blow molding. In the injection molding step, The preform is injection molded such that the thickness of the first bottom portion becomes 1.5 mm or more, or the ratio of the thickness of the first bottom portion to the thickness of the first body portion becomes 0.8 or more. The preform is injection molded such that, in a cross-section of the preform obtained by cutting the preform with a plane along the central axis of the first lip, the angle of inclination of the first body portion relative to the central axis becomes 20° or more and 70° or less. In the injection molding step, the preform is demolded at a high temperature; in the temperature conditioning step, the preform is cooled to a temperature suitable for blow molding; and in the blow molding step, a resin wide-mouth container is formed by stretch blow molding.

3. The manufacturing method according to claim 1, in, In the blow molding step, a resin wide-mouth container is manufactured, the resin wide-mouth container including a second bottom, a second body portion connected to the second bottom, and a second lip portion having a cylindrical wide mouth connected to the second body portion on the opposite side of the second bottom.

4. A hot preform manufacturing apparatus for manufacturing resin wide-mouth containers, comprising at least: An injection molding part is configured as an injection-molded resin base preform, the preform including a first bottom, a first body part connected to the first bottom, and a first lip part having a cylindrical wide mouth connected to the first body part on the opposite side of the first bottom. The first lip part includes a flange part disposed at an edge located on the opposite side of the first body part and protruding outward. as well as The blow molding section is configured to blow mold the injection-molded preform to produce a resin wide-mouth container. The injection molding section is configured to inject molten resin into a space within the shape of the preform to injection mold the preform. This space is formed by a clamping injection core mold, an injection cavity mold, and a lip mold. The lip mold includes a lip periphery defining portion, which is configured to define the outer periphery of the first lip of the preform, excluding the flange portion. The peripheral defining portion of the lip includes a recess, which is configured as a protrusion that extends outward at the upper limit of the outer periphery of the first lip, which is closer to the flange portion than the first body portion. The recess is defined such that the length of the protrusion protruding outward is shorter than the length of the flange protruding outward. With the flange portion held in place by the retaining portion of the lip mold and the recess of the lip mold engaged with the protrusion, the preform is held and demolded.

5. A resin wide-mouth container, comprising: bottom; The main body is connected to the bottom; as well as The lip has a cylindrical wide opening on the side opposite to the bottom that is connected to the body portion. The lip includes a flange portion that protrudes outward from an edge located on the opposite side of the bottom, and a protrusion portion that protrudes outward from the outer periphery of the lip portion closer to the body portion than the flange portion. Wherein, the outer diameter of the lip is the maximum diameter of the wide-mouth container. The outward protrusion of the protrusion is shorter than the outward protrusion of the flange. The lip portion forms a ring-shaped parting line at the position between the protrusion and the body portion.

Images