阅读说明：本技术 树脂容器的生产装置和生产方法 (Resin container production apparatus and production method ) 是由 土屋要一 于 2020-01-31 设计创作，主要内容包括：本发明的目的是提供一种使得即使是借助于具有缩短的成型周期时间的热型坯吹塑也可以生产品质良好的容器的用于树脂容器的生产装置和生产方法。公开了一种用于树脂容器的生产装置(100),包括：注塑部(10),注塑预制件(1)；和温度调节部(20),对通过注塑部(10)成型的预制件(1)的温度进行调节；并且生产装置将通过温度调节部(20)调节了温度的预制件(1)进行吹塑。在预制件(1)的外表面温度比预制件(1)的玻璃化转变温度高30℃至60℃时将预制件(1)引入到温度调节部(20)中,并且通过温度调节部(20)将预制件(1)冷却至适于吹塑的规定温度。(An object of the present invention is to provide a production apparatus and a production method for a resin container that make it possible to produce a container of good quality even by means of hot parison blowing with a shortened molding cycle time. Disclosed is a production apparatus (100) for resin containers, comprising: an injection molding part (10) for injection molding the preform (1); and a temperature adjustment unit (20) that adjusts the temperature of the preform (1) molded by the injection unit (10); and the production apparatus performs blow molding of the preform (1) whose temperature is adjusted by the temperature adjusting section (20). The preform (1) is introduced into a temperature regulating section (20) when the temperature of the outer surface of the preform (1) is 30 ℃ to 60 ℃ higher than the glass transition temperature of the preform (1), and the preform (1) is cooled by the temperature regulating section (20) to a prescribed temperature suitable for blow molding.)

1. A manufacturing apparatus for manufacturing a resin container, characterized by comprising:

an injection molding part configured to injection mold a preform; and

a temperature adjusting part configured to adjust a temperature of the preform molded in the injection part,

wherein the manufacturing apparatus is configured to blow-mold the preform whose temperature has been adjusted in the temperature adjustment section,

wherein the preform is inserted into the temperature adjustment portion in a state where an outer surface temperature of the preform is higher than a glass transition temperature of the preform by 30 ℃ or more and 60 ℃ or less, and

wherein the preforms are cooled in the temperature conditioning section to a predetermined temperature suitable for blow molding.

2. The manufacturing apparatus for manufacturing a resin container according to claim 1, wherein,

the temperature adjustment portion is configured to sandwich the preform with a temperature adjustment core mold and a temperature adjustment cavity mold to compressively deform the preform.

3. The manufacturing apparatus for manufacturing a resin container according to claim 1, wherein,

the temperature conditioning portion is configured to circulate air inside the preform.

4. A manufacturing method for manufacturing a resin container, characterized by comprising:

injection molding the prefabricated part;

adjusting a temperature of the preform on which the injection molding has been performed in a temperature adjusting section; and

the temperature-adjusted preform is blow-molded,

wherein the preform is inserted into the temperature adjusting portion in a state where an outer surface temperature of the preform is higher than a glass transition temperature of the preform by 30 ℃ or more and 60 ℃ or less; and is

Wherein the preforms are cooled in the temperature conditioning section to a predetermined temperature suitable for blow molding.

5. The manufacturing method for manufacturing a resin container according to claim 4, wherein,

the temperature adjustment portion is configured to sandwich the preform with a temperature adjustment core mold and a temperature adjustment cavity mold to compressively deform the preform.

6. The manufacturing method for manufacturing a resin container according to claim 4, wherein,

the temperature conditioning portion is configured to circulate air inside the preform.

7. A manufacturing apparatus for manufacturing a resin container, characterized by comprising:

an injection molding part configured to injection mold a preform; and

a blow molding part configured to blow mold the preform molded in the injection molding part,

wherein the preform is inserted into the blow molding portion after the outer surface temperature of the preform is increased by 80 ℃ or more from the outer surface temperature of the preform at the time of demolding the preform from the injection molding portion, the outer surface temperature of the preform being increased by 80 ℃ or more before 4 seconds or more and 8 seconds or less have elapsed from the demolding of the preform from the injection molding portion.

8. A manufacturing method for manufacturing a resin container, characterized by comprising: an injection molding part configured to injection mold a preform; and a blow molding portion configured to blow mold the preform molded in the injection molding portion, the manufacturing method including:

increasing an outer surface temperature of the preform by 80 ℃ or more than an outer surface temperature of the preform when the preform is ejected from the injection molding part, the outer surface temperature of the preform being increased by 80 ℃ or more before 4 seconds or more and 8 seconds or less have elapsed since the preform was ejected from the injection molding part; and

inserting the preform into the injection molding section.

Technical Field

The present invention relates to a manufacturing apparatus and a manufacturing method for manufacturing a resin container by hot parison blow molding. In particular, the present invention relates to a manufacturing apparatus and a manufacturing method for manufacturing a resin container by hot parison blow molding, which enable the manufacture of a resin container having good appearance and physical properties even if the manufacturing time is shortened.

Background

Conventionally, there is known a blow molding apparatus including: an injection molding part configured to injection mold the preform; a temperature adjusting part configured to adjust a temperature of the preform molded in the injection part; and a blow molding section configured to blow the preform whose temperature is adjusted in the temperature adjustment section (for example, refer to patent document 1). This type of blow molding apparatus is an apparatus that adds a temperature adjustment section to a conventional blow molding apparatus mainly having an injection section and a blow molding section (for example, refer to patent document 2). The preforms immediately after molding in the injection molding section do not have a temperature profile suitable for blow molding. Therefore, a temperature adjustment portion capable of more actively adjusting the temperature of the preform is provided between the injection portion and the blow portion, so that the temperature of the preform can be adjusted to a temperature suitable for blow molding. Note that the temperature adjusting portion uses a heating pot mold (heating block) and a heating rod, and adjusts the temperature of the preform by heating the preform in a non-contact manner.

In addition, there is also a temperature adjustment method in the case of molding a container (cosmetic container) in which only a bottom portion is formed thick. Specifically, there is proposed a blow molding apparatus including a temperature adjusting portion for performing temperature adjustment on a preform of a container so as to provide a temperature distribution suitable for blow molding, in which a bottom portion of the preform and an outer peripheral surface of a lower portion of a body portion continuous with the bottom portion are mechanically brought into close contact with a cooling tank and are reliably cooled, and the body portion other than the lower portion of the body portion continuous with the bottom portion is heated to a predetermined temperature by a heating block, thereby manufacturing a container including a bottom portion having a desired thickness and a body portion having a wall portion stretched with a uniform and thin thickness when performing blow molding (for example, refer to patent document 3). In addition, a blow molding apparatus is proposed which is configured to shorten an injection time that determines a molding cycle time by cooling preforms in an injection section and further cooling the preforms in a temperature adjustment section (for example, refer to patent document 4).

Reference list

Patent document

Patent document 1: JP-A-H06-315973

Patent document 2: WO 2017/098673A 1

Patent document 3: WO 2013/012067A 1

Patent document 4: JP-A-H05-185493

Disclosure of Invention

Technical problem

However, according to the conventional blow molding apparatus, when the cooling time after injection molding is set short, it is not possible to sufficiently remove the temperature unevenness or make the temperature uniform in the temperature adjusting portion. In addition, a method capable of manufacturing a high-quality container that favorably suppresses thickness unevenness and whitening (clouding; which occurs when a thermoplastic resin that may be crystallized during blow molding, such as PET (polyethylene terephthalate), is used as a material) has not been established.

The purpose of the present invention is to provide a manufacturing apparatus and a manufacturing method for manufacturing a resin container, which are capable of manufacturing a container with good quality even by a hot parison blow molding method that shortens the molding cycle time.

Technical scheme for solving problems

The present invention provides a manufacturing apparatus for manufacturing a resin container, the manufacturing apparatus including: an injection molding part configured to injection mold a preform; and a temperature regulating portion configured to regulate a temperature of the preform molded in the injection molding portion, wherein the manufacturing apparatus is configured to blow-mold the preform of which the temperature has been regulated in the temperature regulating portion, wherein the preform is inserted into the temperature regulating portion in a state in which an outer surface temperature of the preform is higher than a glass transition temperature of the preform by 30 ℃ or more and 60 ℃ or less, and wherein the preform is cooled to a predetermined temperature suitable for blow-molding in the temperature regulating portion.

In this case, the temperature regulating portion may be configured to sandwich the preform with the temperature regulating core mold and the temperature regulating cavity mold to compressively deform the preform. The temperature conditioning section may be configured to circulate air inside the preform.

Further, the present invention provides a manufacturing method for manufacturing a resin container, comprising: injection molding the prefabricated part; adjusting the temperature of the preform on which the injection molding has been performed in a temperature adjusting section; and blow-molding the temperature-adjusted preform, wherein the preform is inserted into the temperature adjustment portion in a state where the outer surface temperature of the preform is higher than the glass transition temperature of the preform by 30 ℃ or more and 60 ℃ or less, and the preform is cooled in the temperature adjustment portion to a predetermined temperature suitable for blow-molding.

In this case, the temperature regulating portion may be configured to sandwich the preform with the temperature regulating core mold and the temperature regulating cavity mold to compressively deform the preform. The temperature conditioning section may be configured to circulate air inside the preform.

Further, the present invention provides a manufacturing apparatus for manufacturing a resin container, the manufacturing apparatus including: an injection molding part configured to injection mold a preform; and a blow molding part configured to blow-mold the preform molded in the injection molding part, wherein the preform is inserted into the blow molding part after an outer surface temperature of the preform is increased by 80 ℃ or more from an outer surface temperature of the preform when the preform is demolded from the injection molding part, the outer surface temperature of the preform being increased by 80 ℃ or more before 4 seconds or more and 8 seconds or less have elapsed from the demold of the preform from the injection molding part.

Further, the present invention provides a manufacturing method for manufacturing a resin container, comprising: an injection molding part configured to injection mold a preform; and a blow molding part configured to blow mold the preform molded in the injection molding part, the manufacturing method including: increasing the outer surface temperature of the preform by 80 ℃ or more than the outer surface temperature of the preform when the preform is demolded from the injection molding part, the outer surface temperature of the preform being increased by 80 ℃ or more before 4 seconds or more and 8 seconds or less have elapsed since the preform was demolded from the injection molding part; and inserting the preform into the injection molding section.

The invention has the advantages of

According to the present invention, it is possible to provide a manufacturing apparatus and a manufacturing method for manufacturing a resin container, which can manufacture a container with good quality even by a hot parison blow molding method that shortens a molding cycle time.

Drawings

Fig. 1 is a perspective view of a blow molding apparatus (including an injection molding part, a temperature adjustment part, a blow molding part, and a take-out part) according to one embodiment of the present invention.

Fig. 2 is an enlarged sectional view of the preform injection-molded in the injection-molded portion, seen from the front.

Fig. 3 is a schematic view of the temperature adjusting portion.

Fig. 4 shows another example of the temperature adjustment portion.

Fig. 5 is a sectional view showing a state in which a preform is blow-molded in a blow molding portion.

Fig. 6 is a temperature profile when the temperature of the preform is adjusted.

Detailed Description

Advantageous embodiments of the invention will be described hereinafter with reference to the accompanying drawings.

Fig. 1 is a perspective view of a blow molding apparatus (including an injection molding part, a temperature regulation part, a blow molding part, and a take-out part) according to one embodiment of the present invention, fig. 2 is an enlarged sectional view of a preform injected in the injection molding part as seen from the front, fig. 3 is a sectional view of the temperature regulation part as seen from the front, fig. 4 is an enlarged sectional view of a preform whose temperature is regulated in the temperature regulation part, and fig. 5 is a sectional view showing a state where the preform is blow molded in the blow molding part.

As shown in fig. 1, a blow molding apparatus (a manufacturing apparatus for manufacturing a resin container) 100 is an apparatus including: the injection part 10, the temperature adjustment part 20, the blow molding part 30, and the take-out part 40, and is configured to manufacture the container 1a by injection molding the preform 1 and then blow molding the preform 1.

The injection part 10, the temperature-adjusting part 20, the blow part 30, and the take-out part 40 are arranged to form an arrangement of four sides of a square, as viewed from above. Above these portions, a rotating disk (not shown) is provided, which is provided with a neck mold 50 (see fig. 3) configured to hold a neck 3 (see fig. 2) of a preform 1 molded in the injection molding section 10. The rotating disc has four sets of neck molds 50 arranged to form an alignment of the four sides of the square as viewed from above. Thus, when the rotating disk is rotated 90 degrees in the counterclockwise direction about the vertical axis above the injection part 10, the temperature regulation part 20, the blowing part 30 and the take-out part 40, each of the four sets of neck molds 50 is simultaneously and sequentially moved to the injection part 10, the temperature regulation part 20, the blowing part 30 and the take-out part 40, so that the respective processes are performed for the preforms 1 held by the neck molds 50 for the same time.

The injection part 10 includes an injection core mold 11, an injection cavity mold 12, and an injection device (not shown), and is configured to inject the preform 1.

As shown in fig. 2, the preform 1 has a bottomed shape (bottomed hollow shape) having a neck portion 3 on the open side and a reservoir portion 2 (body portion) 2 on the closed side. The preform 1 is formed into a container 1a (see fig. 5) by blow molding, and has a thick shape obtained by shrinking the container 1a after blow molding in the vertical direction and the horizontal direction in fig. 5. The storage part 2 includes a body part 2a on the open side and continuous with the neck part 3 and a bottom part 2b positioned on the closed side and continuous with the body part 2 a. The injection core mold 11 and the injection cavity mold 12 are formed with a flow path (not shown) that is connected to a cooler and through which a low-temperature (e.g., 5 ℃ or higher and 20 ℃ or lower) coolant flows.

In injection molding of the preform 1, the injection core mold 11, the injection cavity mold 12, and the neck mold 50 are combined to define a space corresponding to the preform 1. At this time, the inner surface shapes of the reservoir 2 and the neck 3 of the preform 1 are formed by the injection core mold 11, the outer surface shape of the reservoir 2 is formed by the injection cavity mold 12, and the outer surface shape of the neck 3 is formed by the neck mold 50.

The injection molding part 10 is configured to form a surface layer (skin) of the reservoir 2, and to mold the preform 1 by: a material such as a thermoplastic synthetic resin (for example, a polyester type resin such as PET (polyethylene terephthalate)) is heated to a high temperature and melted, the melted material is injected and filled into a molding space (cavity) defined by the injection core mold 11, the injection cavity mold 12, and the neck mold 50 by an injection device (not shown), and the material of a portion of the injected material close to the mold surface (cavity surface) is cooled to a temperature lower than the melting point (for example, about 255 ℃ in the case of PET) and solidified. At this time, the inner layer of the storage part 2 of the preform 1 is maintained at a temperature equal to or lower than the melting point and equal to or higher than the glass transition temperature (for example, 150 ℃ to 200 ℃) and adjusted to have heat (residual heat) that can stretch the storage part 2 in the blow molding part 30. Note that, in the present invention, the molding cycle time of the preform 1, i.e., the molding time, is shortened as compared with the prior art. Specifically, of the injection time (filling time) and the cooling time constituting the injection time of the preform, the cooling time is set to be significantly shorter than in the prior art. For example, the cooling time is set to 2/3 or less, preferably 1/2 or less, and more preferably 1/3 or less of the injection time.

The injection core mold 11 is formed such that a cross section of a portion corresponding to the reservoir portion 2 (more specifically, the body portion 2a) of the preform 1 is smaller than a cross section of a portion corresponding to the neck portion 3. Thus, the inside of the injection molded preform 1 is formed such that the internal space area of the reservoir 2 in the direction perpendicular to the axial center Z of the preform 1 is smaller than the internal space area of the neck 3 in that direction.

In addition, the injection core mold 11 is formed such that the cross section becomes gradually smaller toward a position on the mold surface (cavity surface) corresponding to the bottom portion 2b of the preform 1. Thus, the inside of the injection molded preform 1 is formed such that the internal space area expanding in the direction perpendicular to the axial center Z of the preform 1 becomes gradually smaller toward the bottom portion 2b of the preform 1.

The preform 1, which is solidified to some extent after injection in the injection molding section 10 (to the extent that surface layers are formed on the inner and outer surfaces of the reservoir 2 and the outer shape can be maintained), is pulled out (demolded) from the injection cavity mold 12 and the injection core mold while being held on the neck mold 50, and is conveyed to the temperature regulation section 20 as the rotating disk is rotated 90 degrees in the counterclockwise direction, as shown in fig. 1. Since the preform 1 is demolded from the injection part 10 at a higher temperature than the related art, the surface layer of the reservoir part 2 is formed thinner and the inner layer is formed thicker, so that a higher residual heat than the related art is maintained.

The temperature adjusting part 20 is disposed near the injection part 10, and includes: the temperature-adjusting core mold 21 or the air introducing/discharging member 21 a; and a temperature-adjusting cavity mold 22 as shown in fig. 3 and 4.

The preform 1 delivered from the injection molding section 10 moves downward together with the rotating disk until the neck mold 50 comes into contact with the centering ring 60 attached to the temperature-adjusting cavity mold 22 and is inserted into the temperature-adjusting cavity mold 22. When the preform 1 is inserted into the temperature-adjusting cavity mold 22, the temperature-adjusting core mold 21 or the air introduction/discharge member 21a is inserted into the preform 1 through the upper opening formed on the neck portion 3 of the preform 1. Note that, in the case of using the temperature-adjusting core mold 21, the preform 1 may be inserted into the temperature-adjusting cavity mold 22 together with the temperature-adjusting core mold 21 after the temperature-adjusting core mold 21 is inserted into the preform 1.

As the coolant (temperature adjusting medium) flows through the flow paths formed in the temperature-adjusting core mold 21 and the temperature-adjusting cavity mold 22, the temperature-adjusting core mold 21 and the temperature-adjusting cavity mold 22 are cooled to 10 ℃ or more and 90 ℃ or less, preferably 60 ℃ or more and 80 ℃ or less. The air introducing/discharging member 21a is configured to flow compressed air for cooling at a predetermined temperature in the storage part 2. The temperature of the preforms 1 that are ejected from the injection section 10 and transported to the temperature regulation section 20 in a higher temperature state than in the prior art is too high for blow molding, and also has temperature unevenness that has not been completely eliminated by cooling during transport. The preform is cooled and temperature-regulated to a temperature suitable for blow molding by being brought into contact with the temperature-regulating core mold 21 and the temperature-regulating cavity mold 22, or by bringing the outer surface into contact with the temperature-regulating cavity mold 22 and blowing out the compressed air from the air introducing/discharging member 21a to the inner surface.

Fig. 3 shows an example of cooling the reservoir 2 of the preform 1 by the temperature-adjusting cavity mold 22 and the temperature-adjusting core mold 21. The temperature-adjusting core mold 21 is formed with a narrowed portion 23a so as to prevent contact with the neck portion 3 when the temperature-adjusting core mold 21 is inserted into the temperature-adjusting cavity mold 22.

The temperature regulation core mold 21 of the present embodiment has a tapered shape with an angle smaller than that of the tapered injection core mold 11 of the injection part 10. Thus, the preform 1 can be compression-deformed from a shape that can be easily taken out (demolded) or molded from the injection part 10 into a desired shape that can be easily blow-molded.

As shown in fig. 3, the temperature regulation portion 20 is disposed such that the temperature regulation core mold 21 contacts and presses substantially the entire inner surface of the storage portion 2 of the preform 1, and the temperature regulation cavity mold 22 contacts and presses substantially the entire outer surface of the storage portion 2 of the preform 1. Thus, even when the preform 1 is irregularly shrunk and deformed after being demolded from the injection part 10, the shape of the preform 1 can be corrected by sandwiching the reservoir part 2 of the preform 1 between the temperature-adjusting core mold 21 and the temperature-adjusting cavity mold 22. Here, the temperature adjusting portion 20 may adjust the temperatures of the inside and outside of the preform 1 while forcibly compression-deforming the preform 1 having the initial shape during injection molding into the preform 1 having the secondary shape suitable for blow molding into the final container 1a by: the preform 1 is cooled while pressurizing and clamping the preform 1 by the temperature-adjusting core mold 21 and the temperature-adjusting cavity mold 22.

Note that, in the present embodiment, the preform 1 is cooled while being pressurized and sandwiched in the reservoir 2 by the temperature-adjusting core mold 21 and the temperature-adjusting cavity mold 22. However, the present invention is not limited. For example, as shown in fig. 4, an alternative temperature adjusting means having a temperature adjusting cavity mold 22 and an air introducing/discharging member 61 may also be used to cool the preform 1.

Fig. 4 shows an example of cooling the storage part 2 of the preform 1 by the temperature-adjusting cavity mold 22 and the air introducing/discharging member 61. In fig. 4, the air introducing member 61 includes a hollow rod member 62 in which an air flow hole is provided and an assembly core (blowing core member for temperature regulation) 63.

The lever member 62 is accommodated to be movable up and down in the fitting core 63. The tip of the lever member 62 is provided with an inner flow port 62a through which air can be ejected or sucked. The temperature of the air is appropriately set in the range of about 0 deg.c to about 20 deg.c (room temperature) according to the thickness of the preform 1 or the container 1 a.

The fitting core 63 is configured to be fitted to (in close contact with) the neck 3 when the air introducing member 61 is inserted into (in contact with) the preform 1 in an airtight manner. Thus, the air in the preform 1 can be prevented from leaking from the neck portion 3 toward the outside of the fitting core 63. The gap between the rod member 62 and the fitting core 63 is an air flow path for supplying/discharging air with respect to the preform 1. The gap formed by the tip of the fitting core 63 and the rod member 62 constitutes a first outer flow port 64 through which the air can be ejected or sucked. Each of the inner flow port 62a and the outer flow port 64 may function as a blowing port and a discharge port.

In adjusting the temperature of the preform 1, the preform 1 is first accommodated in the preform-shaped space of the temperature-adjusting cavity mold 22. Then, the air introducing member 61 is inserted into (in contact with in an airtight manner) the preform 1 accommodated in the temperature-adjusting cavity mold 22. Then, in a state where the first inner flow port 62a is closed, a preliminary blowing of blowing air into the preform 1 from the outer flow port 64 of the air introducing member 61 to bring the reservoir portion 2 of the preform 1 into close contact with the inner wall of the temperature-adjusting cavity mold 22 is performed.

When the preliminary blowing ends, a cooling blow that opens the inner flow ports 62a to introduce air into the preform 1 from the inner flow ports 62a and discharges the air to the outside of the preform 1 through the outer flow ports 64 is performed. Thus, in the preliminary blowing and the cooling blowing, it is preferable to set the flow direction of the air to the opposite direction. At this time, since air is continuously injected from the inner flow port 62a, the preforms 1 are cooled from the inside by convection of the air flowing inside the preforms 1. Further, since the preform 1 is in continuous contact with the temperature-adjusting cavity mold 22, the preform is temperature-adjusted or cooled from the outside to a temperature below that which does not become suitable for blow molding, and temperature unevenness caused during injection molding is also reduced. Note that, since the temperature-adjusting cavity mold 22 has a space of the preform shape, the shape of the preform 1 does not change greatly. The preform 1 cooled for a predetermined time is moved to the blow molding part 30.

Note that the air flow direction of the air introducing member 61 may be changed as appropriate. For example, as shown in fig. 4, during the cooling blow, air may be sent out from the outer flow port 64, may pass through the interior of the lever member 62 from the inner flow port 62a, and may then be discharged. At this time, during the preliminary blowing, air is preferably fed into the preform 1 from the inner flow port 62a in a state where the outer flow port 64 is closed. In the case where it is intended to increase the cooling effect on the lower side of the preforms 1 (the bottom side of the reservoir 2), air is caused to flow from the inner flow port 62a to the outer flow port 64. In the case where it is intended to increase the cooling effect on the upper side of the preforms 1 (the upper side of the reservoir 2), air is caused to flow from the outer flow port 64 to the inner flow port 62 a. Note that, for example, in the case where it is intended to intensively cool a specific portion of the preform 1 to thereby increase the thickness of a specific portion of the container 1a, the blowing directions of the air during the preliminary blowing and the cooling blowing may be set to be the same.

If the PET material is slowly cooled to a temperature region of about 120 ℃ to 200 ℃, whitening or clouding is caused by crystallization. Therefore, in order to manufacture a highly transparent container 1a (see fig. 5) from the preform 1 released from the injection part 10 in a high temperature state, it is necessary to rapidly cool the preform 1 to a crystallization temperature range or less. At this time, in the case of the preform 1 having the thick-walled portion 5 at the reservoir portion 2, particularly at the body portion 2b, it is difficult to sufficiently cool the center of the wall portion 5 in the related art. However, in the temperature adjusting method shown in fig. 3, the wall portion 5 of the preform 1 is compression-molded even when the wall portion 5 of the preform 1 is thick, whereas in the temperature adjusting method shown in fig. 4, cooling air is blown into the preform 1. Therefore, the efficiency of the temperature unevenness removal, the temperature homogenization, and the cooling can be significantly improved. In addition, since a temperature distribution suitable for the entire blow molding is obtained, it is possible to prevent the thickness unevenness of the container 1a as a final form.

The preform 1 temperature-regulated in the temperature regulation section 20 is pulled out from the temperature regulation cavity mold 22 while being held by the neck mold 50, and is conveyed to the blow molding section 30 as the rotating disk is further rotated 90 degrees in the counterclockwise direction, as shown in fig. 1.

As shown in fig. 1, the blow molding part 30 is disposed adjacent to the temperature adjustment part 20, and has a blow mold 31 and a blow part (not shown).

A mold surface corresponding to the shape of the container 1A is formed on the inner side of the blowing mold 31, and the blowing mold 31 is much larger than the temperature-adjusting cavity mold 22 of the temperature adjusting section 20.

The blowing section is provided to fill air in the preform 1 inserted into the blowing mold 31.

When the preform 1 conveyed to the blow molding section 30 is inserted into the blow mold 31, the blow molding section is connected to the opening of the neck portion 3 of the preform 1, and air is blown from the blow molding section into the preform 1, the storage section 2 of the preform 1 is expanded until the entire outer surface of the storage section 2 is in close contact and pressed to the mold surface of the blow mold 31 as shown in fig. 5, thereby molding the container 1 a.

The preform 1 (container 1a) blown in the blow molding section 30 is pulled out from the blow mold 31 while being held by the neck mold 50, and is conveyed to the take-out section 40 as the rotating disk is further rotated 90 degrees in the counterclockwise direction, as shown in fig. 1.

As shown in fig. 1, the take-out 40 is arranged between the blow molding part 30 and the injection molding part 10. In the extraction portion 40, the neck mold 50 is opened so that the container 1a is no longer held. As a result, the container 1a falls down, so that the container 1a is taken out of the blow molding apparatus 100.

In the blow molding apparatus 100 of the present embodiment, the preform 1 is demolded from the injection cavity mold 12 in a high-temperature state in which the preform 1 is cooled only to such an extent that the outer shape thereof can be maintained. Specifically, the preform 1 is inserted (conveyed) into the temperature regulating section 20 before the outer surface temperature of the body portion 2a of the preform 1 demolded from the injection section 10 (the temperature of the surface layer of the outer peripheral surface of the body portion 2a) becomes higher than the inner surface temperature of the body portion 2a (the temperature of the surface layer on the inner peripheral surface of the body portion 2a), for example, at a temperature at which the outer surface temperature is higher than the glass transition temperature of the preform 1 by 30 ℃ or more and 60 ℃ or less. The temperature regulating section 20 is configured to cool the inner layer via the surface layer so as to reduce the outer surface temperature of the preform 1 by 15 ℃ or more and 30 ℃ or less from the temperature at the time of inserting (transporting) the preform 1 into the temperature regulating section 20. Note that the glass transition temperature of the preform 1 made of PET is, for example, about 75 ℃.

In general, the preform 1 molded in the injection part 10 for a sufficient time tends to be firmly contacted with the injection core mold 11 due to shrinkage of the resin and tends to be separated from the injection cavity mold 12, so that the outer surface temperature of the preform 1 is higher than the inner surface temperature of the preform when it is transferred to the temperature adjusting part. Further, the temperature gradient (thermal gradient) between the inner layer and the surface layer of the preform 1 is relatively small.

On the other hand, the blow molding apparatus 100 of the present embodiment is configured to convey the preforms 1 to the temperature adjustment section 20 at a much higher temperature than in the prior art. Since the preform 1 is demolded from the injection core mold 11 and the injection cavity mold 12 in the injection part 10 in a state where the residual heat of the inner layer is higher than that of the prior art, the temperature gradient between the inner layer and the surface layer becomes larger than that of the prior art. Thus, heat exchange by heat transfer between the inner and surface layers of the preform 1 is actively performed. Thus, the outer surface temperature of the preform 1 is once raised by the return heat (heat transfer from the inner layer to the surface layer) during the conveyance to the temperature regulation section 20, so that the temperature difference between the inner layer and the surface layer is significantly reduced by using the short conveyance time between the injection section 10 and the temperature regulation section 20 (the mold release operation time of the injection section 10 and the conveyance time from the injection section 10 to the next process, for example, 4.0 seconds or more and 12.0 seconds or less, more preferably 4.0 seconds or more and 8.0 seconds or less), promoting temperature uniformity and temperature unevenness removal. Specifically, high temperature demolding promotes heat transfer to such an extent as follows: the temperature of the surface layer of the preform 1 is rapidly increased from a temperature close to the injection mold (e.g., 5.0 ℃ to 20.0 ℃) to a temperature above 110 ℃ and below 130 ℃, thereby improving the effects of homogenizing the temperature and removing the temperature unevenness of the preform 1 (the temperature of the surface layer of the preform 1 is rapidly increased to above 110 ℃ and below 130 ℃ with respect to the set temperature of the injection mold (e.g., 5.0 ℃ or above and below 20 ℃) during the transport time). Meanwhile, during the transport time, the preform 1 is cooled by the outside air, and the surplus heat of the preform 1 generated by the high-temperature demolding is discharged to the outside air, so that the cooling time of the inner layer required for the next process (the temperature adjusting section 20 or the blow molding section 30) is shortened. Therefore, the cooling efficiency of the inner layer of the preform 1 in the temperature adjustment portion 20 and the temperature adjustment efficiency of the inner layer and the surface layer are improved. Therefore, the temperature of the preform can be lowered to a temperature lower than the crystallization temperature range in a short time to adjust the preform to a temperature distribution suitable for stretch orientation in a short time, thereby manufacturing a container having high transparency and physical properties in a short time. Further, due to high temperature demolding, the surface layer of the preform 1 is subjected to high temperature and softened before the next process, so that roughness of the surface layer transferred to the preform 1 from the injection core mold or the injection cavity mold can be eliminated. Therefore, the roughness of the surface layer of the preform 1 immediately before blow molding can be reduced as compared with the prior art, so that a container 1a having small surface roughness and high surface gloss can be manufactured.

Hereinafter, the temperature adjustment of the preform 1 injected in the injection part 10, which is performed in the temperature adjustment part 20, will be specifically described.

FIG. 6 is a temperature profile of the preform as the temperature of the preform is adjusted.

Fig. 6 (a) shows the temperature distribution immediately before the temperature adjustment (cooling) in the temperature adjustment portion. In fig. 6 (a), the horizontal axis indicates the position in the thickness direction, the vertical axis indicates the temperature, the temperature distribution curve C1 indicates the temperature distribution before temperature adjustment of the related art in which a predetermined conveyance time (about 5 seconds, specifically, 4.0 seconds or more and 8.0 seconds or less) has elapsed immediately after mold release, and the temperature distribution curve C2 indicates the temperature distribution before temperature adjustment of the present embodiment in which a predetermined conveyance time (about 5 seconds, specifically, 4.0 seconds or more and 8.0 seconds or less) has elapsed immediately after mold release. Further, in fig. 6 (a), a temperature distribution curve C1a indicates a temperature distribution of the prior art immediately after being released from the injection part 10, and a temperature distribution curve C2a indicates a temperature distribution of the present embodiment immediately after being released from the injection part 10.

Fig. 6 (b) shows the temperature distribution immediately after the temperature adjustment (cooling) in the temperature adjustment portion. In fig. 6 (b), the horizontal axis indicates the position in the thickness direction, the vertical axis indicates the temperature, the temperature distribution curve C3 indicates the temperature distribution after temperature adjustment of the related art, and the temperature distribution curve C4 indicates the temperature distribution before temperature adjustment of the present embodiment. Also, a temperature distribution curve C5 shown by a dotted line indicates a temperature distribution immediately after the temperature of the preform is adjusted using the cold parison method.

In the blow molding apparatus 100 of the present embodiment, as shown by the temperature distribution curves C2 and C2a in (a) of fig. 6, the outer surface temperature of the preform 1 rises from about 20 ℃ to about 120 ℃, i.e., rises by about 100 ℃, within a conveying time of about 5 seconds immediately after the ejection from the injection section 10, and rises rapidly by 80 ℃ or more in a short time. Specifically, in the blow molding apparatus 100 of the present embodiment, as shown by the temperature distribution curve C2 in fig. 6 (a), the preform 1 is inserted into the temperature adjustment part 20 in a state in which the outer surface temperature of the preform 1 is higher by about 30 ℃ (i.e., about 115 ℃) than the glass transition temperature (i.e., about 75 ℃) of the preform 1 made of PET. At this time, the inner surface temperature of the preform 1 was about 117 ℃, and the outer surface temperature was lower than the inner surface temperature.

On the other hand, in the temperature adjustment by the prior art, as shown by the temperature distribution curves C1 and C1a, the outer surface temperature of the preform 1 may be increased from about 20 ℃ to about 80 ℃, that is, only about 60 ℃ during the transport time of about 5 seconds immediately after the demolding from the injection molding section 10. Specifically, in the temperature adjustment by the related art, since the injection molding process is performed for a long time and thus the preform is cooled for a long time, the preform is inserted into the temperature adjustment portion in a state where the outer surface temperature of the preform 1 is about 87 ℃, as shown by the temperature distribution curve C1. At this time, the outer surface temperature is higher than the inner surface temperature.

Since the temperature adjusting section 20 of the present embodiment is configured to adjust the temperature of the preform 1 mainly in the temperature adjusting section 20, the temperature of the outer surface of the temperature-adjusted preform 1 is reduced to about 85 ℃, as shown by a temperature distribution curve C4 in (b) of fig. 6. At this time, the outer surface temperature is higher than the inner surface temperature.

On the other hand, in the temperature adjustment by the prior art, since the heat accumulated at the center of the wall portion of the preform is transferred to the inner and outer surfaces of the preform, the temperature of the outer surface of the temperature-adjusted preform 1 is increased to about 102 ℃, as shown by the temperature distribution curve C3. At this time, the outer surface temperature is higher than the inner surface temperature.

In addition, in the temperature conditioning of the preform produced by the cold parison method, the temperature of the outer surface of the temperature-conditioned preform from the room temperature state was raised to about 100 ℃, as shown by the temperature distribution curve C5. At this time, the outer surface temperature is higher than the inner surface temperature, and the outer surface temperature is substantially the same as the outer surface temperature as shown by the temperature profile C3 which is temperature regulation of the prior art by the hot parison method.

The blow molding apparatus 100 of the present embodiment is configured to insert the preform 1 into the temperature adjustment portion 20 in a state where the outer surface temperature of the preform 1 is higher than the glass transition temperature of the preform 1 by 30 ℃ or more and 60 ℃ or less, and cool the preform 1 to a predetermined temperature suitable for blow molding in the temperature adjustment portion 20. Thus, the injection molding process can be performed in a short time, so that the molding cycle time can be shortened, and the preform can be sufficiently cooled in the temperature regulation part 20. Therefore, even in the hot parison injection mold, a container having good quality can be produced.

Further, under the molding conditions of the present embodiment in which the cooling time in the injection molding process is set to 2/3 or less, preferably 1/2 or less, and more preferably 1/3 or less of the filling time, the preform 1 is released from the injection section 10 in a higher temperature state than in the prior art. Therefore, in a short conveyance time (for example, 4 seconds or more and 12 seconds or less, more preferably 4.0 seconds or more and 8.0 seconds or less) from the injection section 10 to the next step, the temperature of the preform 1 can be made uniform more effectively than in the prior art, and thus the temperature of the preform as a whole can be lowered (heat quantity can be reduced). In addition, the cooling time of the preform 1 or the container 1a in the next step (the temperature adjusting section 20 or the blowing section 30) can be shortened. Therefore, even when the molding cycle time is shortened as compared with the related art, the container 1a in which the appearance defects are suppressed can be manufactured.

Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. For example, in the above-described embodiment, the temperature adjustment portion 20 configured to cool the preform 1 while sandwiching the preform 1 with the temperature adjustment core mold 21 and the temperature adjustment cavity mold to compressively deform the preform 1 is used. However, the present invention is not limited thereto. A temperature adjusting section configured to arrange the preform between the temperature adjusting rod and the temperature adjusting pot and blow air inside the preform from the temperature adjusting rod and circulate it may also be used as long as the outer surface temperature of the preform can be cooled by 15 ℃ or more in the temperature adjusting section.

In the above embodiment, the injection molded preform 1 is cooled using the temperature regulating portion 20. However, the present invention is not limited thereto. If the preforms 1 can be cooled to a predetermined temperature suitable for blow moulding, it is not necessary to use a temperature regulation.

List of reference numerals

1: prefabricated part

2: storage part

3: neck part

4: pouring gate

5: wall part

10: injection molding part

11: injection molding core mold

12: injection cavity mold

1 a: container with a lid

20: temperature adjusting part

21: temperature regulation core mould

22: temperature regulation cavity mold

30: blow molding part

31: blowing mould

40: extraction part

50: neck mold

60: ring (C)

100: blow molding apparatus (manufacturing apparatus for manufacturing resin container)

Z: axial center