Method for producing resin vessel made of resin, mould unit and moulding apparatus

Abstract

A method for manufacturing a resin container (10) having an injection molding process (S1), a temperature control process (S2), and a blow molding process (S3), wherein in the temperature control process (S2), a preform (11) is received in a cavity mold (31), an air introduction member (32) is brought into airtight contact with the preform (11), air is sent into the interior of the preform (11) from the blower port of the air introduction member (32), and air is discharged to the outside of the preform (11) from the outlet port of the air introduction member (32), thereby bringing the preform (11) into close contact with the inner wall of the cavity mold (31) and cooling the preform (11).

Description

Technology Field

[0001] The present invention relates to a method for manufacturing a resin container, a mold unit, and a molding machine. Background Technology

[0002] The hot parison type blow molding method utilizes the heat retained during the injection molding of a preform to perform blow molding. Compared to the cold parison type, this method enables the manufacture of containers with a variety of designs and excellent aesthetic appearances. Hot parison blow molding machines include models equipped with a temperature control unit between the injection molding section and the blow molding section (4-station type) and models without such unit (2-station and 3-station types). When a temperature control unit is present, it is generally easier to adjust the temperature conditions of the preform prior to blow molding to suit the molding of the final container. Furthermore, various methods and devices have been developed for hot parison blow molding machines with the aim of shortening the molding cycle. For example, Patent Documents 1 and 2 aim to shorten the molding cycle by reducing the time for the opening and closing operation of the injection molding die or the lifting and lowering operation of the stretching device, Patent Document 3 by changing the control method of the injection device, and Patent Document 4 by adopting a preform shape capable of early release and the injection molding die thereof. Prior art literature

[0003] : Japanese Patent Publication No. 2005-007797 : International Publication No. 2016-148189 : International Publication No. 2017-002150 : International Publication No. 2017-098673 The problem to be solved

[0004] Recently, there has been a desire for further improvement in the productivity of hot parison blow molding machines, specifically for further shortening of the molding cycle time. To shorten the molding cycle time, it is necessary to shorten the machine-side operating time as described in Patent Documents 1 to 3, but it is also essential to shorten the injection molding time (cooling time) of the preform, which is the rate limiting stage (where the overall processing speed is determined), as described in Patent Document 4.

[0005] However, in Patent Document 4, the adoption of a special preform shape is a mandatory condition. Since the preform needs to be designed with an optimal shape (thickness distribution) according to the shape of the container, Patent Document 4 can only handle the molding of certain types of containers and cannot be said to have high versatility. In particular, the method of Patent Document 4 cannot handle the molding of cosmetic containers (thick containers) that are advantageous for the hot parison method. As such, in hot parison blow molding methods, a highly versatility-based cycle shortening method for various molding modes has not been devised at present.

[0006] Therefore, the present invention aims to provide a method for manufacturing a resin container, a mold unit, and a molding machine that can effectively mold a final molded product while shortening the molding cycle. means of solving the problem

[0007] The method for manufacturing a resin container of the present disclosure capable of solving the above problem is,

[0008] An injection molding process for injection molding a preform made of resin and having a bottom surface, and

[0009] A temperature control process for controlling the temperature of the preform manufactured in the above injection molding process, and

[0010] A method for manufacturing a resin container having a blow molding process for manufacturing a resin container by blow molding the temperature-controlled preform, wherein

[0011] In the above temperature control process,

[0012] The above preform is received in a cavity mold, and

[0013] An air introduction member is brought into airtight contact with the above preform, and

[0014] Air is sent into the interior of the preform from the blower port of the air introduction member, and the air is discharged to the outside of the preform from the outlet port of the air introduction member, thereby adhering the preform to the inner wall of the cavity mold and cooling the preform.

[0015] According to the above configuration, the preform can be cooled from the inside during the temperature control process, thereby shortening the molding cycle and allowing the final molded product to be molded well.

[0016] In the method for manufacturing a resin container of the present disclosure,

[0017] A temperature control medium flows through the above cavity mold, and

[0018] In the above temperature control process, the temperature of the preform is controlled from the outside by close contact with the cavity mold, and

[0019] It is preferable to cool the preform from the inside by convection of air from the air introduction member.

[0020] According to the above configuration, by applying different cooling intensities to the inner and outer sides of the preform, temperature control and cooling can be achieved simultaneously, thereby enabling the final molded product to be formed well while more effectively shortening the molding cycle.

[0021] In addition, the method for manufacturing a resin container of the present disclosure capable of solving the above problem is,

[0022] An injection molding process for injection molding a preform made of resin and having a bottom surface, and

[0023] A temperature control process for controlling the temperature of the preform manufactured in the above injection molding process, and

[0024] A method for manufacturing a resin container having a blow molding process for manufacturing a resin container by blow molding the temperature-controlled preform, wherein

[0025] In the above injection molding process,

[0026] A resin material is injected into the space of the shape of the preform formed by the fastening of the injection molding die, and

[0027] After the injection of the resin material is completed, the resin material is cooled within the space, and

[0028] The time for cooling the resin material in the space after the injection of the resin material is completed is less than or equal to half the time for injecting the resin material.

[0029] According to the above configuration, since the cooling time in the injection molding process can be shortened, the injection molding time of the preform in the injection molding section can be shortened, and thus the molding cycle time of the container itself can be shortened.

[0030] In addition, the mold unit of the present disclosure capable of solving the above problem is,

[0031] A cavity mold that accommodates a preform made of resin and having a bottom surface, and

[0032] A mold unit used in a temperature control process of a preform, comprising an air introduction member that is in airtight contact with the preform and sends air into the interior of the preform,

[0033] The above air introduction member is,

[0034] A vent that sends the above air into the interior of the above preform, and

[0035] An outlet that discharges the above air to the outside of the preform

[0036] Provides.

[0037] According to the above configuration, the preform can be cooled from the inside during the temperature control process, thereby shortening the molding cycle and allowing the final molded product to be molded well.

[0038] In the mold unit of the present disclosure,

[0039] It is preferable that the above cavity mold be a fixed structure rather than a split mold.

[0040] In addition, the molding machine of the present disclosure capable of solving the above problem is

[0041] It is equipped with an injection molding section, a temperature control section, and a blow molding section,

[0042] The above temperature control unit is equipped with the above mold unit.

[0043] In addition, the method for manufacturing a resin container of the present disclosure capable of solving the above problem is,

[0044] An injection molding process for injection molding a preform made of resin and having a bottom surface, and

[0045] A temperature control process for controlling the temperature of the preform manufactured in the above injection molding process, and

[0046] A method for manufacturing a resin container having a blow molding process for manufacturing a resin container by blow molding the temperature-controlled preform, wherein

[0047] The above preform has a thickness of 2.0mm or more and 10.0mm or less, and

[0048] The area ratio of the cross-sectional area including the vertical axis centerline of the container to the cross-sectional area including the vertical axis centerline of the preform is 1.2 times or more and 10.0 times or less, and

[0049] In the above temperature control process, the preform is cooled from the inside. Furthermore, the method for manufacturing a resin container according to the present disclosure capable of solving the above problem comprises at least: an injection molding process in which a molten resin material is injected into a space of the shape of a preform formed by fastening an injection molding die in a vertical direction to injection mold a preform having a bottom surface; a blow molding process in which the preform is blow-molded to manufacture a resin container; and a conveying process in which the neck portion of the preform is supported by a neck die attached to a rotating plate, and the preform is conveyed to each process by the rotation of the rotating plate. In the injection molding process, when the temperature of at least the inner layer of the preform is higher than the temperature range at which crystallization of the resin material occurs and the preform becomes white, the preform is released from the injection molding die in a high-temperature state, and the temperature range at which the preform becomes white is a temperature range at which crystallization by the formation of spherical crystals is promoted. In order to suppress whitening of the preform that has been released in a high-temperature state, the preform is cooled by releasing retained heat to the outside from the first surface layer, which is the space side of the inner side of the preform, after the preform is released from the injection molding mold in a high-temperature state. In order to suppress the whitening of the above preform, the preform is cooled from the end of the injection molding process to the start of the blow molding process so that the temperature of the inner layer of the preform does not fall below the temperature of the inner layer of the preform at the start of the blow molding process.In the above blow molding process, after receiving the preform in a blow molding mold, the preform is stretched downward by a rod member, and at the same time, air is sent into the interior of the preform from an air introduction member to bulge into the shape of a container. Furthermore, the manufacturing apparatus for a resin container according to the present disclosure capable of solving the above problem comprises, at least, an injection molding mold including an injection cavity mold and an injection core mold, an injection molding unit that injects a molten resin material into a space of the shape of a preform formed by the injection molding mold being fastened in a vertical direction to injection mold a preform having a bottom surface, a blow molding unit that manufactures a resin container by blow molding the preform, and a conveying means that supports the neck portion of the preform by a neck mold attached to a rotating plate and conveys the preform to each part by the rotation of the rotating plate, wherein the injection molding unit, when the temperature of at least the inner layer of the preform causes crystallization of the resin material to occur When the temperature is higher than the temperature range at which the preform becomes white, the preform is configured to be released from the injection core mold and the injection cavity mold in a high-temperature state, and the temperature range at which the preform becomes white is a temperature range at which crystallization by the formation of spherical crystals is promoted. In order to prevent the above-mentioned preform from whitening, the preform is cooled from the end of the injection molding process to the start of the blow molding process so that the temperature of the inner layer of the preform does not fall below the temperature of the inner layer of the preform at the start of the blow molding process. In order to suppress whitening of the preform released from the injection molding mold in a high-temperature state, the preform is cooled by releasing retained heat to the outside from the surface layer portion, which is the space side of the inner side of the preform, after the preform is released from the injection molding mold in a high-temperature state, and the blow molding portion comprises a blow molding mold that receives the preform, a rod member that extends the preform received in the mold downward, and an air introduction member that sends air into the interior of the preform to make it bulge into the shape of a container. Effects of the invention

[0050] According to the present invention, a method for manufacturing a resin container, a mold unit, and a molding machine can be provided, which can effectively mold a final molded product while shortening the molding cycle. Brief explanation of the drawing

[0051] Fig. 1 is a block diagram of a molding machine. FIG. 2 is a schematic cross-sectional view showing the temperature control state of the preform (air blowing direction of the cooling blower) in the temperature control unit of the first embodiment. FIG. 3 is a cross-sectional schematic diagram showing the state of blow molding for manufacturing a container from a preform in the blow molding section of the first embodiment, from (a) to (b). FIG. 4 is a diagram showing a flowchart of a method for manufacturing a resin container. FIG. 5 is a diagram showing the change in temperature of a preform over time in a first embodiment and a reference example, wherein (a) represents the first embodiment and (b) represents the reference example. FIG. 6 is a schematic cross-sectional view showing the state of a modified example of temperature control of a preform in the temperature control unit of the first embodiment (air blowing direction of the cooling blow). FIG. 7 is a comparison diagram of a preform appropriately used in an embodiment and a preform of a reference example, (a) showing two preforms (the left one has a thin thickness and the right one has a normal thickness) and an image of a container blow-molded from them, and (b) showing an image of heat exchange between preforms of different thicknesses. FIG. 8 is a schematic cross-sectional view showing the temperature control state of the preform in the temperature control unit of the second embodiment from (a) to (d). FIG. 9 is a cross-sectional schematic diagram showing the state of blow molding for manufacturing a container from a preform in the blow molding section of the second embodiment, from (a) to (d). FIG. 10 is a drawing showing the change in temperature over time of a preform in a second embodiment and a reference example, wherein (a) represents the second embodiment and (b) represents the reference example. Specific details for implementing the invention

[0052] (First embodiment)

[0053] Hereinafter, an example of an embodiment of the present invention (a first embodiment) will be described with reference to the drawings. Additionally, for convenience of explanation, the dimensions of each component shown in the drawings may differ from the actual dimensions of each component. First, with reference to FIG. 1, a molding machine (20) for manufacturing a resin container (10) will be described. FIG. 1 is a block diagram of the molding machine (20).

[0054] As shown in FIG. 1, the molding machine (20) is equipped with an injection molding unit (21) for manufacturing a preform (11) and a temperature control unit (22) for adjusting the temperature of the manufactured preform (11). An injection device (25) for supplying a resin material, which is a raw material, is connected to the injection molding unit (21). In addition, the molding machine (20) is equipped with a blow molding unit (an example of a blow device) (23) for manufacturing a container (10) by blowing the preform (11) and an extraction unit (24) for taking out the manufactured container (10).

[0055] The injection molding section (21), the temperature control section (22), the blow molding section (23), and the ejection section (24) are installed at positions rotated by a predetermined angle (90° in this embodiment) around the conveying means (26). The conveying means (26) is composed of a rotating plate, etc., and as shown in FIGS. 2 and 3, the preform (11) or container (10), in which the neck section (12) is supported by a neck mold (27) attached to the rotating plate, is configured to be conveyed to each section according to the rotation of the rotating plate.

[0056] The injection molding section (21) shown in FIG. 1 is equipped with an injection cavity mold, an injection core mold, a neck mold, etc., which are omitted from the drawing. A synthetic resin material, such as a polyester resin (e.g., PET: polyethylene terephthalate), is introduced from an injection device (25) into a space of the preform shape formed by combining these molds, thereby manufacturing a preform (11) having a bottom surface. The preform (11) has an optimal thickness distribution (shape) according to the container (10), and the thickness of the body part (average thickness, thickness) is set to, for example, 1.0 to 5.0 mm, preferably 1.5 to 3.0 mm.

[0057] The temperature control unit (22) is configured to adjust the temperature of the preform (11) manufactured in the injection molding unit (21) to a suitable temperature for final blowing.

[0058] Here, with reference to FIG. 2, the temperature control unit (22) will be described in detail. As shown in FIG. 2, the temperature control unit (22) is equipped with a mold unit (30) having a cavity mold (temperature control cavity mold) (31) that accommodates a preform (11) for temperature control blowing, and a first air introduction member (32) that is in airtight contact with the preform (11) to send air into the interior of the preform (11). The cavity mold (31) has a fixed (single unit) structure, rather than an openable split mold, which defines a space with a shape approximately identical to the preform (11) manufactured in the injection molding unit (21). The cavity mold (31) is configured to be divided into two sections vertically, having an upper mold (31a) and a lower mold (3lb). Also, the cavity mold (31) shown in FIG. 2 is provided with a support (37) at the bottom of the lower mold (3lb). A temperature control medium (cooling medium) flows inside each of the upper mold (31a) and the lower mold (3lb) to maintain a low temperature. Although the temperature of the temperature control medium flowing inside each of the upper mold (31a) and the lower mold (3lb) is not specifically limited, it is possible to appropriately select a range of, for example, 5°C to 80°C, preferably between 30°C and 60°C. In addition, depending on the size and shape of the preform (11), the lower mold (3lb) of the cavity mold (31) shown in FIG. 2 may be made into an intermediate mold, a cavity corresponding to the preform may be formed in the support (37) to form the lower mold, and a temperature control medium (cooling medium) may be made to flow inside it, thereby configuring it into three stages.

[0059] The first air introduction member (32) is composed of a first rod member (33) which is hollow and has an air passage hole formed inside, and a first fitting core (first blow core member) (34). The first rod member (33) is accommodated inside the first fitting core (34) so ​​as to be able to move up and down. A first inner direction flow port (35) capable of ejecting or sucking air is formed at the tip of the first rod member (33). The temperature of the air is appropriately set within a range of, for example, about 0°C to about 20°C (room temperature), depending on the thickness of the preform (11) or the container (10). The first fitting core (34) is configured to be fitted into the neck portion (12) (closely in contact) when the first air introduction member (32) is inserted into the preform (11) (contacted in a hermetic manner). Accordingly, it is possible to prevent air inside the preform (11) from leaking from the neck portion (12) to the outside of the first fitting core (34). The gap between the first rod member (33) and the first fitting core (34) is an air circulation path for supplying and discharging air to the preform (11). The gap formed by the tip of the first fitting core (34) and the first rod member (33) forms a first outer direction circulation port (36) capable of ejecting or sucking in air. The first inner direction flow port (35) and the first outer direction flow port (36) can each be a blower port and an exhaust port.

[0060] Next, the blow molding section (23) will be described with reference to FIG. 3. As shown in FIG. 3, the blow molding section (23) is equipped with a mold (40) and a second air introduction member (50). The mold (blow mold) (40) is composed of a bottom mold (42) and a pair of split molds (blow molding cavity molds) (43) that can be opened and closed. By connecting the bottom mold (42) and the split molds (43), the external shape of the side and bottom surfaces of the container (10) is defined. The bottom mold (42) is positioned at the lower center of the molding space of the split molds (43).

[0061] The second air introduction member (50) provided by the blow molding section (23) is composed of a second rod member (51) and a second fitting core (second blow core member) (52). The second rod member (51) is accommodated so as to be able to move up and down inside the second fitting core (52). The second rod member (51) is an elongation rod, and a contact portion (55) is formed at the tip to contact the inner bottom surface of the preform (11) to prevent center deviation during elongation. On the outer surface of the second rod member (51), a second inner direction flow port (53) capable of ejecting or sucking in air is formed. The second fitting core (52) is configured to be fitted into the neck portion (12) (closely in contact) when the second air introduction member (50) is inserted into the preform (11) (contacted in a hermetic manner). Accordingly, it is possible to prevent air inside the preform (11) from leaking from the neck portion (12) to the outside of the second fitting core (52). The gap between the second rod member (51) and the second fitting core (52) is a flow path for supplying and discharging air to the preform (11). The gap formed by the tip of the second fitting core (52) and the second rod member (51) forms a second outer direction flow port (54) capable of ejecting or sucking in air.

[0062] The second air introduction member (50) is configured to send air into the interior of the preform (11) from the second outer direction flow port (54) and discharge it to the outside of the preform (11) from the second inner direction flow port (53). The second inner direction flow port (53) and the second outer direction flow port (54) can each serve as a blower port and a discharge port.

[0063] Next, a method for manufacturing a container (10) according to the first embodiment will be described. FIG. 4 is a diagram showing a flowchart of a method for manufacturing a resin container. The container (10) of the present embodiment is manufactured by going through an injection molding process (S1) in which a preform (11) is injection molded, a temperature control process (S2) in which the temperature of the preform (11) is controlled, and a blow molding process (S3) in which the temperature-controlled preform (11) is blow-molded to manufacture the container (10), and the container (10) is taken out by opening the neck portion (12) from the neck mold (27).

[0064] First, the injection molding process (S1) will be described. In the injection molding process (S1), a preform (11) is manufactured by introducing a resin material from an injection device (25) into a space of the preform shape formed by combining an injection cavity mold, an injection core mold, a neck mold, etc. Immediately after the completion of the resin filling process or after a cooling process of a set time (at least) set after the resin filling process, the preform (11) is moved from the injection molding unit (21) to the temperature control unit (22).

[0065] In the injection molding process (S1), the start-up time (t) 10 From )(time when injection of the resin material begins) the first time (t 11 Between ) and ), a resin material is injected into a space of the preform shape (Fig. 5(a)). The first time (t 11 From )(time when the inflow of resin material is completed) the second time (t 12 Between ) and ), the preform (11) is heated to the first temperature (T 11 From ) the second temperature (T 12 Cool to ) (Fig. 5(a)). First temperature (T 11 ) is a temperature above the melting point of the resin material, for example, 270 to 300°C for PET resin. Start-up time (t 10 From ) the first time (t 11 ) is the charging time (injection time), the first time (t 11 From ) the second time (t 12 ) is cooling time, starting time (t 10From ) the second time (t 12 ) becomes the injection molding time (IT11) (filling time (including pressure holding time) + cooling time). Also, the second time (t 12 From ) the third hour (t 13 During the period up to (start time of the temperature control process (S2)), the preform (11) is at a second temperature (T 12 From ) the third temperature (T 13 It is cooled until ) (Fig. 5(a)). The second hour (t 12 From ) the third hour (t 13 ) is the return time (DT11) of the preform (11) or container (10) between each process, and in FIG. 5, it represents the time for returning the preform (11) from the injection molding unit (21) to the temperature control unit (22). Also, due to the structure of the molding machine (20), the return time (DT11) between processes is the same value. The sum of the injection molding time (IT11) and the return time (DT11) is the molding cycle time (CT11).

[0066] Time for cooling the resin material after the injection of the resin material is completed (first time (t 11 From ) the second time (t 12 The time up to ) is the time for injecting the resin material (startup time (t 10 From ) the first time (t 11 It is preferable that the cooling time for the resin material in the injection molding process be 1 / 2 or less of the time up to ). In addition, depending on the weight of the resin material, the cooling time for the resin material in the injection molding process can be made shorter than the injection time for the resin material. It is more preferable that the cooling time for the resin material be 1 / 3 or less of the injection time for the resin material, even more preferable that it be 1 / 4 or less, and particularly preferable that it be 1 / 5 or less.

[0067] Next, the temperature control process (S2) is described with reference to FIG. 2. First, the preform (11) is received within the space of the preform shape of the cavity mold (31). Next, a first air introduction member (32) is inserted into the interior of the preform (11) received in the cavity mold (31) (making contact so as to be airtight). Then, with the first inner direction flow port (35) closed, air is sent into the interior of the preform (11) from the first outer direction flow port (36) of the first air introduction member (32) to perform a preliminary blow that presses the preform (11) against the inner wall of the cavity mold (31). Next, the first inner direction flow port (35) is opened, and while introducing air from the first inner direction flow port (35), a cooling blow (cooling blow) is performed to discharge air to the outside of the preform (11) through the first outer direction flow port (36) (Fig. 2). In this way, it is preferable to set the direction of air flow in opposite directions during the pre-blow and cooling blow. At this time, since air is continuously ejected from the first inner direction flow port (35), the preform (11) is cooled from the inside by the convection of the air flowing inside. In addition, since the preform (11) is in continuous contact with the cavity mold (31), the temperature is controlled so that it does not fall below the temperature suitable for blow molding from the outside, and the temperature deviation that occurs during injection molding is also reduced. Also, since the cavity mold (31) has a space of the preform shape, the shape of the preform (11) does not change significantly. After cooling for a certain period of time, the cooled preform (11) is moved to the blow molding section (23).

[0068] In addition, the direction of air flow in the first air introduction member (32) can be appropriately changed. For example, as shown in FIG. 6, in a cooling blow, air may be sent from the first outer direction flow port (36) and discharged from the first inner direction flow port (35). In this case, for the preliminary blow, it is preferable to send air into the interior of the preform (11) from the first inner direction flow port (35) while the first outer direction flow port (36) is closed. If you want to increase the cooling intensity of the lower side (bottom side) of the preform (11), air is flowed from the first inner direction flow port (35) toward the direction of the first outer direction flow port (36). If you want to increase the cooling intensity of the upper side (body side) of the preform (11), air is flowed from the first outer direction flow port (36) toward the direction of the first inner direction flow port (35). In addition, when you want to increase the thickness of a specific part of the container (10) by strongly cooling a specific part of the preform (11), it is acceptable to set the airflow direction of the pre-blow and the cooling blow to be the same.

[0069] Here, referring again to FIG. 5, the change in temperature of the preform over time is explained. In the temperature control process (S2), the third time (t 13 From ) the fourth intermediate time (t 14' Between ) and ), the preform (11) is heated to the third temperature (T 13 From ) the fourth temperature (T 14 Cool until ), and then the 4th hour (t 14 Between ) the fourth temperature (T 14 The temperature of the preform (11) is maintained at ) (Fig. 5(a)). The fourth temperature (T 14 ) is the temperature suitable for blowing, and for example, in the case of PET resin, it is set to 90℃ to 105℃. 3rd time (t 13 From ) the fourth hour (t 14 The time up to ) is the temperature control time (TT11). Also, the fourth temperature (T 14 ) indicates the appropriate temperature for preform blowing. The fourth intermediate time (t 14') after the fourth hour (t 14 During the period up to ), temperature control in the temperature control process (S2) continues until the molding (cooling) of the preform (11) in the injection molding process (S1) is completed. Also, the fourth temperature (T 14 When the time to reach ) becomes shorter, the fourth intermediate time (t 14' The cooling blow may be stopped at the point of ). Also, the fourth temperature (T 14 Since the lower temperature allows for better elongation orientation of the preform (11) and thus increases the strength (physical properties) of the container (10), it is preferable to set the temperature to 90 to 95°C.

[0070] Next, the blow molding process (S3) will be described with reference to FIG. 3. First, a preform (11) is placed in a mold (40) in which the bottom mold (42) is stopped and the split mold (43) is open. Next, the split mold (43) is closed (Fig. 3(a)), and a second air introduction member (50) is inserted (made into airtight contact). At this time, the preform (11) is stretched in the downward direction in FIG. 3 by means of the second rod member (51). Then, by a final blow sending air into the interior of the preform (11) from the second outer direction flow port (54), the preform (11) is bulged to the shape of a container (10) to manufacture a container (10) (Fig. 3(b)). If cooling is insufficient due to contact between the mold (40) and the preform (11), a cooling blow may be performed after the final blow by sending air into the interior of the preform (11) from the second inner direction flow port (53) and discharging air to the outside of the preform from the second outer direction flow port (54). After the final blow is completed, the split mold (43) is opened to open the container (10) from the mold (40).

[0071] The container (10) extracted from the mold (40) is moved to the extraction section (24) (Fig. 1), and the container (10) is removed by opening the neck section (12) from the neck mold (27). The container (10) is manufactured by the above method.

[0072] However, when a hot parison type preform (11) is molded using a crystalline thermoplastic resin (a resin that can be in a transparent amorphous state and a cloudy crystalline state), depending on the material, it may turn white due to insufficient cooling. For example, when PET (polyethylene terephthalate) is used as the material, if it is cooled slowly (for example, cooling for several tens of seconds at room temperature) in a temperature range (120°C to 200°C) where crystallization is promoted, crystallization occurs due to the formation of spherical crystals, and it tends to turn white (cloudy). Therefore, conventionally, the injection molding mold (injection cavity mold, injection core mold, neck mold) was rapidly cooled (for example, at 10°C for 5 seconds) to shorten the time passing through the crystallization temperature range and sufficiently cooled during the injection molding process, thereby suppressing the crystallization (whitening) of the PET preform (11). That is, as shown in FIG. 5(b), in the conventional method of manufacturing a resin container, during the injection molding process, a first time (t 21 From ) the second time (t 22 Between ) and ), the preform is at the first temperature (T 21 From ) the fourth temperature (T 24 A second temperature (T) that is lower than or approximately equal to (an appropriate temperature for blow forming, for example, 90–105°C). 22 It was cooling until ). And in the temperature control process, the third hour (t 23 From ) the fourth intermediate time (t 24' Between ) and ), the preform is at the third temperature (T 23 From ) the fourth temperature (T 24 The temperature rises until ), and then the fourth hour (t 24 Between ) the fourth temperature (T 24The temperature of the preform (11) was maintained (Fig. 5(b)). Because of this, the cooling time in the injection molding process was prolonged, and consequently, the molding cycle time (CT21) of the container was prolonged. Also, when molding a container with a thick thickness, more time is required for cooling the preform, and the molding cycle time (CT21) of the container becomes even longer (Fig. 5(b)). Furthermore, if a special PET resin (copolyester: copolymer) modified to be difficult to crystallize is used, it is possible to manufacture a preform or container with suppressed whitening while shortening the cooling time in the injection molding part of the preform (11) to some extent. However, this special PET resin is very expensive compared to general-purpose (conventional) PET resin, so it is not desirable for mass production of general-purpose containers.

[0073] According to the method for manufacturing a resin container (10) of the present embodiment, the cooling process of the preform (11) in the injection molding process (S1) is completely eliminated, and the cooling process of the preform (11) is moved to the temperature control process (S2). In the temperature control process (S2), the preform (11) is brought into close contact with the cavity mold (31) so that the outer surface of the preform (11) can be effectively temperature controlled. In addition, since convection occurs by allowing air to flow continuously without being trapped inside the preform (11), the inner surface of the preform (11) can be cooled simultaneously. Since the temperature control and cooling of the preform (11) are performed in the temperature control process (S2), the preform (11) can be released even in a high-temperature state during the injection molding process (S1), and the molding of the next preform (11) can be started quickly. In other words, the final molded product can be formed well while shortening the molding cycle time (CT11). Furthermore, even when using general-purpose PET resin instead of special PET resin, containers that do not whiten can be molded with a short molding cycle.

[0074] However, in Patent Document 4, the body shape of the preform is designed to be thin in order to enable early demolding during the injection molding process. This is effective as a measure to shorten the molding cycle in a blow molding machine without a temperature control process. However, if the preform shape is made thin, there is a concern that the physical properties or appearance of the container (10) will deteriorate. Therefore, a case is described in which a container of the same shape is manufactured from preforms of the same weight but different body thicknesses. FIG. 7(a) shows two preforms of 40g (the left one is thin thickness, the right one is normal thickness) and an image drawing of the external shape (dotted line) of a container blow-molded from each preform. The thin-thickness preform has a thin body and is elongated in the vertical axis direction (left side of FIG. 7(a)). As a result, the elongation ratio in the vertical axis direction of the thin preform becomes smaller compared to the normal thickness preform. Generally, the higher the elongation ratio (orientation elongation), the higher the strength (impact strength against drops, stiffness, tensile strength, etc.) and barrier properties of the container. In other words, containers molded from thin-walled preforms have inferior physical properties compared to containers molded from standard-walled preforms. Furthermore, as the elongation ratio decreases, it becomes difficult to control the container thickness, which tends to lead to poor thickness accuracy and appearance. Thin-walled preforms (left side of Fig. 7(a)) also fall short of standard-walled preforms (right side of Fig. 7(a)) in terms of temperature uniformity. Fig. 7(b) is an image diagram of heat exchange between preforms of different thicknesses. Compared to standard-walled preforms, the heat content of the inner layer (core) of the thin-walled preform is lower, so the degree of heat transfer (heat exchangeability) with the lower-temperature surface layer (skin layer) deteriorates. As a result, compared to preforms of normal thickness, thin preforms are difficult to homogenize in terms of temperature, making it easy for the thickness of the container to increase.

[0075] In this embodiment, since the preform (11) can be efficiently cooled in the temperature control unit (22), the molding cycle time (CT11) can be shortened even when using a preform designed to have an optimal thickness distribution to match the shape of the container, unlike Patent Document 4. In addition, the risk of degradation of the physical properties of the container or whitening is small, making it highly versatile.

[0076] In addition, the preform (11) used in the present invention is preferably set so that the average thickness of the body portion is 2.0 mm or more and 10.0 mm or less (preferably 2.0 mm or more and 5.0 mm or less). In addition, it is preferable that the longitudinal elongation ratio of the preform (11) of the container (10) is set so that it is 1.1 times or more and 4.0 times or less (preferably 1.1 times or more and 1.2 times or 1.9 times or more and 4.0 times or less), and the transverse elongation ratio is set so that it is 1.1 times or more and 4.0 times or less (preferably 1.1 times or more and 1.8 times or less or 3.0 times or more and 4.0 times or less). In addition, it is desirable that the area ratio (area ratio of the longitudinal section) of the cross-sectional area including the longitudinal axis centerline of the container (10) is set to be 1.2 times or more and 16.0 times or less (preferably 1.2 times or more and 10.0 times or less). In particular, it is more desirable that the longitudinal elongation ratio is set to about 2.5 times, the transverse elongation ratio to about 4.0 times, and the area ratio to about 10.0 times. By setting the values ​​of the molding conditions of the preform (11) as above, and by molding the preform (11) from a general-purpose (conventional) PET resin and implementing the above temperature control method, it becomes possible to properly manufacture a container (10) with high strength (physical properties) and suppressed whitening (cloudiness).

[0077] (Example of the first embodiment)

[0078] Hereinafter, an embodiment of the first embodiment will be described. Furthermore, the technical scope of the present invention is not limited to this embodiment. The technical scope of the present invention is defined within the scope described in the claims or an equivalent scope.

[0079] Using a molding machine (20) having the configuration described in the first embodiment, manufacturing tests of PET containers of Examples 1, 2, and 3 were conducted. The thickness of the preform (average thickness of the body part), cycle time, weight of the container, and content of the container for each example are as shown in Table 1. The time for injecting the resin material in the injection molding process, the time for cooling the preform inside the mold after injection is completed, and the chiller temperature (temperature of the cooling medium (chiller water)) inside the injection cavity mold of the injection molding part for each example are as shown in Table 1. The blow time of the preform in the temperature control process and the temperatures of the upper temperature control POT, middle temperature control POT, and lower temperature control POT of the cavity mold for each example are as shown in Table 1. Also, in Example 1, a two-stage cavity mold without a middle temperature control POT was used, and in Examples 2 and 3, a three-stage cavity mold was used.

[0080]

[0081] In the manufacturing tests of Examples 1, 2, and 3, no whitening of the preform occurred, allowing for the production of containers with good shapes. Furthermore, under conditions where cooling by pre-blow and cooling blow was not performed in the temperature control process, compared to the case where cooling was performed in the injection molding process to prevent whitening of the preform, a reduction in cycle time of 24.3% in Example 1, 13.0% in Example 2, and 37.5% in Example 3 was achieved. Since the cooling time in the injection molding process becomes longer when the preform thickness is thick and the weight is large, a reduction in cycle time was particularly achieved in Example 3.

[0082] (Second embodiment)

[0083] Next, another example of an embodiment of the present invention (second embodiment) will be described with reference to FIGS. 1, FIGS. 4 and FIGS. 8 to 10. The molding machine (120) ( FIG. 1) according to the second embodiment has a configuration that is identical or similar to the molding machine (20) according to the first embodiment, except that the configuration of the cavity mold (131) of the mold unit (130) in the temperature control unit (122), and the configuration of the mold (140) and the second air introduction member (150) provided in the blow molding unit (123) are different. Therefore, identical or similar configurations are given the same reference numerals and their descriptions are omitted. Hereinafter, only the temperature control unit (122) and the blow molding unit (123), which are different from the first embodiment, will be extracted and described.

[0084] First, the temperature control unit (122) will be described in detail with reference to FIG. 8. FIG. 8 is a cross-sectional schematic diagram showing the temperature control state of the preform (11) in the temperature control unit (122) from (a) to (d). Details of each step in FIG. 8(a) to FIG. 8(d) will be described later. The temperature control unit (122) is equipped with a cavity mold (131) that accommodates the preform (11) for temperature control blowing, and a mold unit (130) equipped with a first air introduction member (32). The cavity mold (131) is a divided mold that defines a space larger than the preform (11) manufactured in the injection molding unit (21). The cavity mold (131) maintains a low temperature by having a temperature control medium (cooling medium) flowing inside it. The temperature of the temperature control medium (cooling medium) is not specifically limited, but, for example, between 5°C and 80°C, preferably between 5°C and 30°C, and more suitably within the range of 10°C ± 5°C. The configuration of the first air introduction member (32) is the same as that of the first embodiment.

[0085] The blow molding section (123) will be described in detail with reference to FIG. 9. FIG. 9 is a cross-sectional schematic diagram showing the state of blow molding from (a) to (d) for manufacturing a container (10) from a preform (11) in the blow molding section (123). Details of each step (a) to (d) will be described later. The mold (blow mold unit) (140) provided by the blow molding section (123) is composed of a shoulder mold (141), a bottom mold (142), and a base mold (body part mold) (143). The bottom mold (142) and the base mold (143) are connected to each other to define the external shape of the side and bottom surfaces of the container (10). The bottom mold (142) and the base mold (143) are connected to the second fixing plate (145) at their lower ends. The base mold (143) is configured as a single-structure mold rather than a split mold having a roughly cylindrical molding space, and can move in the up and down direction in FIG. 9. In addition, the inner wall surface of the molding space of the base mold (143) is tapered, and the diameter of the upper space is larger than the diameter of the lower space. The shoulder mold (141) is composed of a pair of split molds, and they are each connected to the first fixing plate (144) at either the left or right end in FIG. 9. The first fixing plate (144) is connected to a mold opening and closing mechanism not shown in the drawing, and the shoulder mold (141) can move in the left and right direction in FIG. 9. The shoulder mold (141) is fitted into the neck mold (27) in a closed state and comes into contact with or close to the shoulder of the preform (11) to define the shape of the shoulder of the container (10). In addition, pressure receiving members not shown in the drawing are disposed on both sides of the shoulder mold (141) (in FIG. 9, the sides in the front and rear directions of the paper surface) and are each connected to the first fixing plate (144).

[0086] The second air introduction member (150) provided by the blow molding section (23) is identical to the first embodiment except for the second rod member (151). The second rod member (151) is the same as the first embodiment in that it has an air flow penetration hole inside, but there is no contact part at its tip that contacts the inner bottom surface of the preform (11), and instead, a second inner direction flow opening (153) capable of ejecting or sucking air is formed.

[0087] The molding machine (120) of the present embodiment manufactures a container (10) with a raised bottom and a thick thickness. The elongation ratio from the preform (11) to the container (10) is intentionally set low. The manufactured preform (11) is thick, and the thickness of the body portion may be, for example, 3.0 to 12.0 mm, preferably 4.0 to 8.0 mm. In addition, the filling capacity of the container (10) may be, for example, 30 to 100 mL.

[0088] Next, the method of manufacturing the container (10) according to the second embodiment is described. The method of manufacturing the container (10) according to the second embodiment is manufactured by going through an injection molding process (S101) in which a preform (11) is injection molded, a temperature control process (S102) in which the temperature of the preform (11) is controlled, and a blow molding process (S103) in which the temperature-controlled preform (11) is blow-molded to manufacture the container (10) (Fig. 4), and the container (10) is taken out by opening the neck portion (12) from the neck mold (27).

[0089] The injection molding process (S101) follows the same operation as the injection molding process (S1) of the first embodiment. Here, with reference to FIG. 10, the change in temperature of the preform over time in the injection molding process (S101) is described. FIG. 10 is a diagram showing the change in temperature of the preform over time in the second embodiment and a reference example, where (a) represents the second embodiment and (b) represents the reference example. In the injection molding process (S101), the first time (t 31From )(time when the inflow of resin material is completed) the second time (t 32 Between ) and ), the preform (11) is heated to the first temperature (T 31 From ) the second temperature (T 32 Cool to ) (Fig. 10(a)). First temperature (T 31 ) is a temperature above the melting point of the resin material, for example, 270 to 300°C for PET resin. Start-up time (t 30 From ) the first time (t 31 ) is the charging time (injection time), the first time (t 31 From ) the second time (t 32 ) is cooling time, starting time (t 30 From ) the second time (t 32 ) becomes the injection molding time (IT31) (filling time (including pressure holding time) + cooling time). Also, the second time (t 32 From ) the third hour (t 33 During the period up to (start time of the temperature control process (S102)), the preform (11) is at a second temperature (T 32 From ) the third temperature (T 33 It is cooled to ) (Fig. 10(a)). The second hour (t 32 From ) the third hour (t 33 ) is the return time (DT31) of the preform (11) or container (10) between each process, and in FIG. 10, it represents the time for returning the preform (11) from the injection molding unit (21) to the temperature control unit (121). Also, due to the structure of the molding machine (120), the return time (DT31) between processes is the same value. The sum of the injection molding time (IT31) and the return time (DT31) is the molding cycle time (CT31).

[0090] Next, the temperature control process (S102) will be described with reference to FIG. 8. First, the preform (11) is moved between the open cavity molds (131), and the cavity molds (131) are closed to receive the preform (11) into the cavity molds (131) (Fig. 8(a)). Next, a first air introduction member (32) is inserted into the preform (11) received in the cavity molds (131) (making a tight seal) (Fig. 8(b)). Then, with the first outer air passage (36) closed, air is sent into the interior of the preform (11) from the first inner air passage (35) of the first air introduction member (32) to perform a preliminary blow that causes the preform (11) to bulge and adhere to the inner wall of the cavity molds (131). Next, the first outer direction flow port (36) is opened, and air is discharged from the first outer direction flow port (36) of the first air introduction member (32) to the outside of the preform (11) to perform cooling blowing (Fig. 8(c)). At this time, since air is continuously ejected from the first inner direction flow port (35), the preform (11) is also cooled from the inside by the air flowing inside. After cooling for a certain period of time, the cavity mold (131) is opened (Fig. 8(d)), and the bulging preform (11) is moved to the blow molding section (123).

[0091] Here, referring again to FIG. 10, the change in temperature of the preform over time is explained. In the temperature control process (S102), the third time (t 33 From ) the fourth intermediate time (t 34' Between ) and ), the preform (11) is heated to the third temperature (T 33 From ) the fourth temperature (T 34 Cool until ), and then the 4th hour (t 34 Between ) the fourth temperature (T 34 The temperature of the preform (11) is maintained at ) (Fig. 10(a)). The fourth temperature (T 34) is a temperature suitable for blow molding, for example, in the case of PET resin, it is set to 90°C to 105°C (preferably 90°C to 95°C, as in the first embodiment). 4th time (t 34 After ), cooling in the temperature control process (S102) continues until cooling of the preform in the injection molding process (S101) is completed.

[0092] Next, the blow molding process (S103) will be described with reference to FIG. 9. First, a preform (11) is received in a mold (140) in which the bottom mold (142) and base mold (143) are stopped and the shoulder mold (141) is open (Fig. 9(a)). Next, the shoulder mold (141) is closed and fitted into the neck mold (27), and a second air introduction member (150) is inserted (made into airtight contact) (Fig. 9(b)). Then, the preform (11) is bulged to the shape of a container (10) by a final blow that sends air into the interior of the preform (11) from the second outer direction flow port (54). After that, a container (10) is manufactured by a cooling blow that sends air into the interior of the preform (11) from the second inner direction air passage (153) and discharges air to the outside of the preform from the second outer direction air passage (54) (Fig. 9(c)). After the final blow and cooling blow are completed, the bottom mold (142) and the base mold (143) are lowered slightly, and then the shoulder mold (141) is opened to pull the container (10) out of the mold (140). Also, if cooling is sufficiently achieved by contact between the mold (140) and the preform (11), the cooling blow may be omitted.

[0093] The container (10) extracted from the mold (140) is moved to the extraction unit (24), and the container (10) is removed by opening the neck unit (12) from the neck mold (27). The container (10) is manufactured by the above method.

[0094] However, as shown in FIG. 10(b), in a conventional method for manufacturing a resin container, in the injection molding process, a first time (t41 From )(time when the inflow of resin material ended) the second time (t 42 Between ) and ), the preform is at the first temperature (T 41 From ) the fourth temperature (T 44 A second temperature (T) that is lower than or approximately equal to ) 42 It was cooling until ). And in the temperature control process, the third hour (t 43 From ) the fourth hour (t 44 During the period up to ), the preform was heated from the third temperature (T43) to the fourth temperature (T44). Because of this, the cooling time in the injection molding process was prolonged, and as a result, the molding cycle time (CT41) of the container was prolonged. In addition, when molding a container with a thick thickness, more time was required for cooling the preform, and the molding cycle time (CT41) of the container was prolonged.

[0095] According to the method of manufacturing a resin container (10) of the present embodiment, the preform (11) can be cooled not only in the injection molding process (S101) but also in the temperature control process (S102). In particular, in the temperature control process (S102), by sending air into the interior of the preform (11), the preform (11) can be bulged and pressed against the cavity mold (131), thereby effectively cooling the outer surface of the preform (11) and obtaining a preform (11) with an appropriate shape. In addition, since convection occurs by allowing the air to flow continuously without being trapped inside the preform (11), the inner surface of the preform (11) can also be cooled simultaneously, allowing the preform (11) to be cooled faster than in the conventional method. In addition, by cooling in the temperature control process (S102), the preform (11) in the injection molding process (S101) can be released even at a high temperature, allowing the molding of the next preform (11) to be started quickly. That is, the injection molding process (S101) and the temperature control process (S102) can work together to effectively cool the preform (11), thereby shortening the molding cycle time (CT31) and allowing the final molded product to be molded well.

[0096] In addition, for a thick preform (11), even if the outer wall of the preform (11) is cooled from one side, it is difficult to cool the inside of the outer wall and the side opposite to the side being cooled, so a long time is required to cool it to an appropriate temperature for blow molding. According to the manufacturing method of the resin container (10) of the present embodiment, in the temperature control process (S102), the outer surface of the preform (11) is effectively cooled, and a thin preform (11) with an appropriate outer shape (an outer shape close to the container (10)) can be obtained, and the inner surface of the preform (11) can also be cooled simultaneously, so a thick preform (11) can be cooled effectively and quickly compared to the conventional method. In addition, by cooling in the temperature control process (S102), the preform (11) in the injection molding process (S101) can be removed from a high-temperature state and moved to the next process, so that the molding of the next preform (11) can be started quickly, thereby shortening the molding cycle and allowing the final molded product to be molded well.

[0097] In addition, according to the mold unit (130) of the present embodiment, by providing a first air introduction member (32) having a first inner direction flow port (35) and a first outer direction flow port (36), convection can be generated by allowing air to flow continuously without being trapped inside the preform (11). Accordingly, the preform (11) can be effectively cooled from the inner surface of the preform (11). In addition, the preform (11) can be bulged by the air and pressed against the cavity mold (131), thereby effectively cooling the outer surface of the preform (11) and obtaining a preform (11) with an appropriate shape.

[0098] In addition, according to the mold unit (130) of the present embodiment, the outer surface of the preform (11) can be effectively cooled to obtain a preform (11) of a suitable shape, and the inner surface of the preform (11) can also be cooled simultaneously, so a preform (11) with a thicker thickness than conventional ones can be effectively cooled quickly.

[0099] Furthermore, the present invention is not limited to the embodiments described above, and appropriate modifications and improvements may be made. In addition, the material, shape, dimensions, numerical values, form, number, placement location, etc., of each component in the embodiments described above are optional and not limited as long as they enable the achievement of the present invention.

[0100] In the blow molding section of the above embodiment, although a second rod member (51) used for cooling blowing has been described, any blow device capable of properly bulging the preform (11) into the container (10) can be used. For example, it does not have to be a blow device in which the blowing and discharging of air alternates through the second inner direction flow port (53) and the second outer direction flow port (54).

[0101] In addition, the opening and closing direction of the mold in the injection molding section is preferably in the vertical direction (longitudinal direction). For instance, if the opening and closing direction of the mold is in the horizontal direction (horizontal direction), the preform released from the injection molding section is in a highly softened state due to the high temperature, and there is a possibility that the lower side of the preform extending in the horizontal direction may bend downward due to the center of gravity during transport to the temperature control section, making it impossible to perform cooling blow on the preform in its normal shape. On the other hand, when the opening and closing direction of the mold in the injection molding section is in the vertical direction (longitudinal direction), such bending deformation does not occur, and cooling blow can be performed on the preform in its normal shape.

[0102] In addition, this application is based on Japanese patent application (JP2017-202716) filed on October 19, 2017, the entirety of which is by reference. Also, all references cited herein are identical in whole. Explanation of the symbols

[0103] 10: Courage 11 : Freeform 12 : Neck part 20, 120 : Molding machine 21 : Injection molding section 22, 122: Temperature control unit 23,123 : Blow forming section 24 : Extraction unit 25 : Injection device 26 : Return means 27 : Neck mold 30, 130: Mold Unit 31, 131: Cavity mold 32 : First air introduction component 33 : First rod member 34 : First fitting core (first blow core member) 35: First inner direction flow opening 36: First outer direction circulation port 40, 140 : Mold 141 : Shoulder mold 42, 142 : Bottom mold 43 : Split mold 143 : Base mold 50, 150 : Second air introduction component 51, 151 : Second rod member 52 : Second fitting core (second blow core member) 53, 153: Second inner direction flow opening 54: Second outer direction circulation port

Claims

Claim 1 At least, the method comprises an injection molding process for injecting a molten resin material into a space of the shape of a preform formed by fastening an injection molding die in a vertical direction to injection mold a preform having a bottom surface, a blow molding process for manufacturing a resin container by blow molding the preform, and a conveying process for supporting the neck portion of the preform by a neck die attached to a rotating plate and conveying the preform to each process by the rotation of the rotating plate, wherein in the injection molding process, when the temperature of at least the inner layer of the preform is higher than the temperature range at which crystallization of the resin material occurs and the preform becomes white, the preform is released from the injection molding die in a high-temperature state, the temperature range at which the preform becomes white is a temperature range at which crystallization by the formation of spherical crystals is promoted, and in order to suppress the whitening of the preform released in a high-temperature state, after releasing the preform from the injection molding die in a high-temperature state Cooling the preform by releasing retained heat to the outside from the first surface layer, which is the space side on the inner side of the preform, and In order to suppress the whitening of the above preform, the preform is cooled from the end of the injection molding process to the start of the blow molding process so that the temperature of the inner layer of the preform does not fall below the temperature of the inner layer of the preform at the start of the blow molding process. A method for manufacturing a resin container, wherein, in the above blow molding process, the preform is received in a blow molding mold, and the preform is stretched downward by a rod member, and air is sent into the interior of the preform from an air introduction member to bulge into the shape of a container. Claim 2 A method for manufacturing a resin container according to claim 1, wherein the retained heat is transferred from the inner layer to the surface layer of the preform that has been molded in a high-temperature state, and the retained heat is released from the surface layer to the outside, thereby cooling the preform. Claim 3 A method for manufacturing a resin container according to claim 2, wherein the temperature of the surface layer of the preform that has been released from the injection molding process and has elapsed for a predetermined time is higher than the temperature of the surface layer of the preform immediately before being blow-molded in the blow molding process. Claim 4 A method for manufacturing a resin container, wherein, in any one of claims 1 to 3, the preform is cooled by promoting the release of retained heat from a second surface portion, which is the outer space side of the preform that was molded in a high-temperature state. Claim 5 A method for manufacturing a resin container according to any one of claims 1 to 3, wherein the average thickness of the body portion of the preform is 2.0 mm or more and 10.0 mm or less. Claim 6 A method for manufacturing a resin container according to any one of claims 1 to 3, wherein the area ratio of the cross-sectional area including the longitudinal axis centerline of the container to the cross-sectional area including the longitudinal axis centerline of the preform is 1.2 times or more and 10.0 times or less. Claim 7 At least, the injection molding unit comprises an injection molding mold including an injection cavity mold and an injection core mold, and injects a molten resin material into a space of the shape of a preform formed by the injection molding mold being fastened in a vertical direction to inject and inject a preform having a bottom surface; the blow molding unit manufactures a resin container by blow molding the preform; and the injection molding unit comprises a neck mold attached to a rotating plate to support the neck portion of the preform and a conveying means to convey the preform to each part by the rotation of the rotating plate, wherein the injection molding unit is configured to release the preform from the injection core mold and the injection cavity mold in a high-temperature state when the temperature of at least the inner layer of the preform is higher than the temperature range at which crystallization of the resin material occurs and the preform becomes white, and the temperature range at which the preform becomes white is a temperature range at which crystallization by the formation of spherical crystals is promoted. In order to prevent the above-mentioned preform from whitening, the preform is cooled from the end of the injection molding process to the start of the blow molding process so that the temperature of the inner layer of the preform does not fall below the temperature of the inner layer of the preform at the start of the blow molding process. A manufacturing apparatus for a resin container, wherein, in order to suppress whitening of the preform released from the injection molding mold in a high-temperature state, the preform is cooled by releasing retained heat to the outside from the surface layer portion which is the space side of the inner side of the preform after releasing the preform in a high-temperature state, and the blow molding portion comprises a blow molding mold that receives the preform, a rod member that extends the preform received in the mold downward, and an air introduction member that sends air into the interior of the preform to make it bulge into the shape of a container. Claim 8 delete Claim 9 delete Claim 10 delete Claim 11 delete Claim 12 delete Claim 13 delete Claim 14 delete

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