阅读说明：本技术 树脂容器制造设备、温度调节装置、树脂容器制造方法及温度调节方法 (Resin container manufacturing facility, temperature control device, resin container manufacturing method, and temperature control method ) 是由 荻原学 长崎淳 堀内一宏 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即使是通过缩短成型周期时间的热型坯式注射吹塑法也能够制造品质良好的容器的吹塑装置、和温度控制装置。公开了一种吹塑装置(100),其中,注塑成形预制件(1),由温度调节单元对注塑成形的预制件(1)进行温度控制,并且吹塑成形温度调节后的预制件(1),其中,温度调节单元20具有多段结构,其中,最上段(22a)具有最高温度结构,并且最上段(22a)以外的下段(22b)和(22c)的模具表面温度设定为比预制件(1)的玻璃化转变温度低10℃以上。(The invention aims to provide a blow molding device and a temperature control device which can manufacture a container with good quality even by a hot parison type injection blow molding method which shortens the molding cycle time. Disclosed is a blow molding device (100) wherein a preform (1) is injection molded, the injection molded preform (1) is temperature-controlled by a temperature adjustment unit, and the temperature-adjusted preform (1) is blow molded, wherein the temperature adjustment unit (20) has a multi-stage structure in which the uppermost stage (22a) has the highest temperature structure, and the mold surface temperatures of the lower stages (22b) and (22c) other than the uppermost stage (22a) are set to be 10 ℃ or higher lower than the glass transition temperature of the preform (1).)

1. A resin container manufacturing apparatus, characterized by being configured to injection mold a preform, adjust the temperature of the injection molded preform in a temperature adjusting stage, and blow mold the temperature-adjusted preform,

wherein the temperature control stage has a multi-stage structure in which the uppermost stage has the highest temperature, and the mold surface temperature of the lower stage other than the uppermost stage is lower than the glass transition temperature of the preform by 10 ℃ or more.

2. The resin container manufacturing apparatus according to claim 1, wherein a mold surface temperature of the lower section is 30 ℃ or more and 80 ℃ or less in a case where a thickness of the preform is 1.5mm or more and 3.0mm or less.

3. The resin container manufacturing apparatus according to claim 1, wherein a mold surface temperature of the lower section is 10 ℃ or more and 60 ℃ or less in a case where a thickness of the preform is 3.0mm or more and 5.0mm or less.

4. The resin container manufacturing apparatus according to claim 1, wherein the temperature adjustment stage is configured to sandwich and compressively deform the preform using a temperature adjustment core mold and a temperature adjustment cavity mold.

5. The resin container manufacturing apparatus according to claim 1, wherein the temperature adjustment stage is configured to circulate air inside the preform.

6. A method of manufacturing a resin container, comprising:

injection molding a prefabricated part;

adjusting the temperature of the injection molded preform in a temperature adjustment station; and

blow molding the temperature-conditioned preform,

wherein the temperature regulation stage has a multi-stage structure in which an uppermost stage has a highest temperature, and a lower stage other than the uppermost stage has a mold surface temperature lower than a glass transition temperature of the preform by 10 ℃ or more.

7. A method of temperature conditioning for blow molding of preforms, the method characterized by comprising:

adjusting the temperature of a temperature adjusting device having a multi-stage structure such that the uppermost stage has the highest temperature; and

the temperature of the preform is adjusted in a state where the mold surface temperature of the lower section other than the uppermost section is lower than the glass transition temperature of the preform by 10 ℃ or more.

8. An apparatus for manufacturing a resin container, comprising:

an injection station configured to injection mold a preform;

a temperature adjustment stage configured to adjust a temperature of the injection molded preform; and

a blow molding station configured to blow mold the temperature conditioned preform,

wherein the injection molding station comprises an injection molding core mold, an injection molding cavity mold and a neck mold which limit the molding space of the preform,

wherein a time for cooling the preform in the molding space is below 2/3 of a time for injecting a resin material to be molded into the preform into the molding space,

wherein the temperature regulation stage includes a temperature regulation tank having a multi-stage structure which is composed of a plurality of stages aligned in an up-down direction and is capable of independently setting the temperature of each stage, and

wherein the temperature regulation tank is configured to cool the preform at different temperatures along the up-down direction while being in contact with an outer surface of the preform.

9. The resin container manufacturing apparatus according to claim 8, wherein the temperature adjustment stage is configured to sandwich the preform and cool the preform using a temperature adjustment core mold and a temperature adjustment cavity mold.

10. The resin container manufacturing apparatus according to claim 8, wherein the temperature adjustment stage is configured to circulate air inside the preform.

11. The resin container manufacturing apparatus according to claim 10, wherein a temperature of a section near a portion where air flows into the preform interior is set higher than a temperature of a section where the air flows out.

12. The resin container manufacturing apparatus according to claim 8, wherein the temperature regulation tank is configured to be in contact with the body portion and the bottom portion of the preform on a housing surface formed as one surface without a boundary, and

wherein there is a groove portion between the segments on the outside of the temperature regulation tank.

13. A method of manufacturing a resin container, comprising:

injection molding the preform in an injection molding station;

adjusting the temperature of the injection molded preform in a temperature adjustment station; and

blow molding the temperature conditioned preform in a blow molding station,

wherein the injection molding station comprises an injection molding core mold, an injection molding cavity mold and a neck mold which limit the molding space of the preform,

wherein a time for cooling the preform in the molding space is below 2/3 of a time for injecting a resin material to be molded into the preform into the molding space,

wherein the temperature adjustment stage includes a temperature adjustment tank having a multi-stage structure composed of a plurality of stages aligned in an up-down direction, and capable of independently setting the temperature of each stage, and

wherein the temperature regulation tank is configured to cool the preform at different temperatures along the up-down direction while being in contact with an outer surface of the preform.

Technical Field

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

Background

The related art discloses a blow molding apparatus including: an injection molding station configured to injection mold a preform; a temperature adjustment stage configured to adjust a temperature of the preform molded in the injection molding stage; and a blow molding station configured to blow the preforms whose temperature has been adjusted in the temperature adjustment station (for example, refer to patent document 1). This type of blow molding apparatus is an apparatus that adds a temperature regulation stage to a conventional blow molding apparatus mainly including only an injection stage and a blow molding stage (for example, refer to patent document 2). The preforms immediately after being formed in the injection molding station do not have a temperature profile suitable for blow molding. Therefore, a temperature regulation stage capable of more actively regulating the temperature of the preforms is provided between the injection and blow moulding stages, so that the temperature of the preforms can be regulated to a temperature suitable for blow moulding. Note that the temperature adjusting stage 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 a temperature adjusting method used when blow molding a container configured to contain cosmetics or the like, in which only a bottom portion is thickened. In particular, a blow-moulding plant is proposed, which comprises a temperature conditioning station for conditioning the preforms of the containers so as to provide a temperature profile suitable for blow-moulding. The bottom portion of the preform and the outer peripheral surface of the lower body portion continuous with the bottom portion are mechanically brought into close contact with the cooling tank and reliably cooled, and the body portion other than the lower body portion continuous with the bottom portion is heated to a predetermined temperature by the heating block. Therefore, a container is manufactured which includes 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 (specifically, a cooling time) that determines a molding cycle time by cooling preforms in an injection station and further cooling the preforms in a temperature adjustment station (for example, refer to patent document 4).

Reference list

Patent document

Patent document 1: JP-A-H06-315973

Patent document 2: WO2017/098673

Patent document 3: WO2013/012067

Patent document 4: JP-A-H05-185493

Disclosure of Invention

Technical problem

However, according to the blow molding apparatus of the related art, when the cooling time after injection molding is set short, the temperature unevenness or the equilibrium temperature cannot be sufficiently removed in the temperature adjusting stage. Therefore, 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.

Further, since the injection-molded preform is conveyed while the neck mold holds the neck, the neck is excessively cooled.

The purpose of the present invention is to provide a resin container manufacturing facility, a temperature control table, a resin container manufacturing method, and a temperature control method, which enable the manufacture of a resin container of 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 resin container manufacturing apparatus configured to injection mold a preform, adjust a temperature of the injection molded preform in a temperature adjustment stage, and blow mold the temperature-adjusted preform, wherein the temperature adjustment stage has a multi-stage structure in which an uppermost stage has a highest temperature, and a mold surface temperature of a lower stage other than the uppermost stage is lower than a glass transition temperature of the preform by 10 ℃ or more.

In this case, when the thickness of the preform is 1.5mm or more and 3.0mm or less, the mold surface temperature of the lower section is 30 ℃ or more and 80 ℃ or less. When the thickness of the preform is 3.0mm or more and 5.0mm or less, the mold surface temperature of the lower section is 10 ℃ or more and 60 ℃ or less. The temperature adjustment stage is configured to sandwich and compressively deform the preform using a temperature adjustment core mold and a temperature adjustment cavity mold. The temperature conditioning station is configured to circulate air inside the preform.

The present invention provides a method for manufacturing a resin container, including: injection molding a prefabricated part; adjusting the temperature of the injection molded preform in a temperature adjustment station; and blow molding the temperature-adjusted preform, wherein the temperature adjustment stage has a multi-stage structure in which an uppermost stage has a highest temperature, and a mold surface temperature of a lower stage other than the uppermost stage is lower than a glass transition temperature of the preform by 10 ℃ or more.

The invention provides a method for temperature regulation in blow moulding of preforms, comprising: adjusting the temperature of a temperature adjusting device having a multi-stage structure such that the uppermost stage has the highest temperature; and adjusting the temperature of the preform in a state where the mold surface temperature of the lower section other than the uppermost section is lower than the glass transition temperature of the preform by 10 ℃ or more.

The present invention provides a resin container manufacturing apparatus, including: an injection station configured to injection mold a preform; a temperature adjustment stage configured to adjust a temperature of an injection molded preform; and a blow molding station configured to blow mold the temperature-adjusted preform, wherein the injection molding station includes an injection core mold, and a neck mold that define a molding space of the preform, a time for cooling the preform in the molding space is below 2/3 of a time for injecting a resin material to be molded into the preform into the molding space, the temperature adjustment station includes a temperature adjustment tank of a multi-stage structure, the multi-stage structure is composed of a plurality of stages aligned in an up-down direction, and a temperature of each stage can be independently set, and the temperature adjustment tank is configured to cool the preform at different temperatures in the up-down direction while being in contact with an outer surface of the preform.

In this case, the temperature-adjusting stage may be configured to sandwich the preform and cool the preform using the temperature-adjusting core mold and the temperature-adjusting cavity mold. The temperature conditioning station may be configured to circulate air inside the preform. The temperature of the section near the portion where air flows into the interior of the preform may be set higher than the temperature of the section where air flows out. The temperature regulation tank may be configured to contact the body portion and the bottom portion of the preform on a receiving surface formed as one surface without a boundary, and may have a groove portion between the sections on an outer side of the temperature regulation tank.

The present invention provides a method for manufacturing a resin container, including: injection molding the preform in an injection molding station; adjusting the temperature of the injection molded preform in a temperature adjustment station; and blow-molding the temperature-adjusted preform in a blow-molding station, wherein the injection station includes an injection core mold, an injection cavity mold, and a neck mold that define a molding space of the preform, a time for cooling the preform in the molding space is below 2/3 of a time for injecting a resin material to be molded into the preform into the molding space, the temperature-adjusting station includes a temperature-adjusting pot having a multi-stage structure, the multi-stage structure is composed of a plurality of stages aligned in an up-down direction, and a temperature of each stage can be independently set, and the temperature-adjusting pot is configured to cool the preform at different temperatures in the up-down direction while being in contact with an outer surface of the preform.

The invention has the advantages of

According to the present invention, it is possible to provide a resin container manufacturing apparatus, a temperature adjustment table, a resin container manufacturing method, and a temperature adjustment method that enable the manufacture of a resin container of 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 station, a temperature adjustment station, a blow molding station, and a take-out station) according to a first embodiment of the present invention.

Fig. 2 is a sectional view of the temperature adjustment stage seen from the front.

Fig. 3 is a cross-sectional view of a second segment according to a second embodiment.

Fig. 4 is a top and bottom view of the second segment according to the second embodiment.

Fig. 5 is a sectional view of a temperature adjustment stage according to a second embodiment.

Fig. 6 is a sectional view of a half of the temperature adjustment stage according to the third embodiment, seen from the front.

Fig. 7 shows a first section of a temperature-regulating stage according to a third embodiment.

Fig. 8 shows a second section of a temperature-regulating stage according to a third embodiment.

Fig. 9 shows a third section of the temperature adjustment stage according to the third embodiment.

Fig. 10 shows a fixing plate of the temperature adjustment stage according to the third embodiment.

Fig. 11 is a sectional view of the temperature adjustment stage according to the fourth embodiment, seen from the front.

Fig. 12 is a sectional view of a temperature adjustment stage according to a fifth embodiment.

FIG. 13 is a top view and a cross-sectional view of a ring plate according to a fifth embodiment.

Fig. 14 is a sectional view of a half of the temperature adjustment stage according to the sixth embodiment, seen from the front.

Detailed Description

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

First embodiment

Fig. 1 is a perspective view of a blow molding apparatus (including an injection molding station, a temperature regulation station, a blow molding station, and a take-out station) according to a first embodiment of the present invention, and fig. 2 is a sectional view of the temperature regulation station as seen from the front.

As shown in fig. 1, a blow molding apparatus (resin container manufacturing apparatus) 100 includes an injection molding station 10, a temperature regulation station (temperature regulation device) 20, a blow molding station 30, and a take-out station 40, and manufactures a container 1a by injection molding a preform 1 and then blow molding the preform.

The injection station 10, the temperature conditioning station 20, the blow station 30 and the take-off station 40 are arranged in an arrangement forming four sides of a square, as seen from above. Above these tables there is provided a rotating disc (not shown) provided with a neck mold 50 (conveying section) configured to hold the neck 3 of the preform 1 molded in the injection station 10. Four sets of neck molds 50 are arranged on a rotating disc in an alignment forming four sides of a square, as seen from above. Thus, when the rotating disk is rotated by 90 degrees in the counterclockwise direction about the vertical axis above the injection stage 10, the temperature regulation stage 20, the blowing stage 30, and the take-out stage 40, each of the four sets of neck molds 50 is simultaneously moved sequentially to the injection stage 10, the temperature regulation stage 20, the blowing stage 30, and the take-out stage 40, so that the respective steps are performed for the same time for the preforms 1 held with the neck molds 50.

The injection molding station 10 includes an injection core mold 11, an injection cavity mold 12, and an injection molding device (not shown), and injects the preform 1.

The preform 1 includes a neck portion 3 on an open side and a reservoir portion 2 (body portion) 2 on a closed side, and is formed into a bottomed shape (bottomed hollow shape). The preform 1 is blow-molded into a container 1a, and has a shape of a thick thickness obtained by shrinking the blow-molded container 1a in the up-down direction in fig. 1. The storage part 2 includes a body part 2a continuous with the neck part 3 on the open side and a bottom part 2b positioned on the closed side and continuous with the body part 2 a.

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 core mold 11 and the injection cavity mold 12 are each 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 circulates.

The injection molding station 10 heats and melts a material such as a thermoplastic synthetic resin (for example, a polyester type resin such as PET (polyethylene terephthalate)) at a high temperature. An injection device (not shown) of the injection molding station 10 injects and fills a molten material into a molding space (cavity) defined by the injection core mold 11, the injection cavity mold 12, and the neck mold 50. The injection molding station 10 cools a portion of the injection material near the mold surface (cavity surface) to a temperature (e.g., 20 ℃) lower than the melting point (e.g., about 255 ℃ in the case of PET) and solidifies the portion of the injection material to form a skin (skin) on the reservoir 2 and mold the preform 1. At this time, the inner layer (core layer) of the reservoir 2 of the preform 1 is maintained at a temperature (for example, 150 ℃ to 20 ℃) equal to or lower than the melting point and equal to or higher than the glass transition temperature, and the reservoir 2 has heat sufficient to stretch in the blow molding station 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 related art. Specifically, of the injection time (filling time) and the cooling time associated with the injection time of the preform, the cooling time is set to be significantly shorter than in the related art. For example, the cooling time for cooling the preform 1 in the molding space is 2/3 or less, preferably 1/2 or less, and more preferably 1/3 or less of the injection time of the resin material to be molded into the molding space.

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 adjacent to the reservoir 2 in the direction perpendicular to the axis Z of the preform 1 is smaller than the internal space area adjacent to the neck 3.

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 area of the inner space 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 station 10 (to the extent that a skin is formed on the inner and outer surfaces of the reservoir 2 and thereby the outer shape can be maintained), is raised together with the rotating disk while being held on the neck portion mold 50, is pulled out (demolded) from the injection core mold 11 and the injection cavity mold 12, and is conveyed to the temperature adjusting station 20 as the rotating disk is rotated 90 degrees in the counterclockwise direction, as viewed from above. Since the preform 1 is released from the injection table 10 at a higher temperature than the related art, the surface layer of the reservoir 2 is formed thinner and the inner layer is formed thicker, thus maintaining a higher residual heat than the related art.

The temperature adjustment stage 20 is disposed adjacent to the injection stage 10, and as shown in fig. 2, includes a temperature adjustment rod (cooling rod) 21a of a hollow pipe shape, a blow core 21 for temperature adjustment, and a temperature adjustment tank 22.

When the preform 1 made of a crystalline thermoplastic resin such as PET is slowly cooled to a temperature region where crystallization is promoted (for example, about 120 ℃ to 200 ℃), whitening (clouding) due to crystallization is caused. Therefore, in order to manufacture the highly transparent container 1a, it is necessary to rapidly cool the preform 1 injected in the injection molding station 10 to the crystallization temperature region or less.

The preforms 1 delivered from the injection molding station 10 are moved downward together with the rotating disk until the neck molds 50 come into contact with the centering ring 60 attached to the temperature-adjusting pot 22 and are inserted into the temperature-adjusting pot 22. When the preform 1 is inserted into the temperature adjustment tank 22, the temperature adjustment rod 21a is inserted into the preform 1 through an opening formed on the neck portion 3 of the preform 1. In addition, the blow core 21 for temperature adjustment is fitted or contacted to the inner peripheral surface or the upper end surface of the opening of the neck portion 3. Note that, after the temperature adjustment rod 21a is inserted into the preform 1, the preform 1 may be inserted into the temperature adjustment tank 22 together with the temperature adjustment rod 21 a.

One end of the temperature adjustment rod 21a is formed to have a cylindrical shape and is configured to be inserted into the temperature adjustment tank 22, and the other end has a first connection portion 21b for connection to a compressor (not shown) and a second connection portion 21c for connection to the atmosphere via a pipe or the like (not shown). Thus, in a state where the temperature adjustment rod 21a is inserted into the preforms 1 arranged in the temperature adjustment tank 22 and the temperature adjustment core 21 is assembled, the compressed air (cooling air) pressure-fed from the compressor passes through the inside of the temperature adjustment rod 21a or the inside of the cylindrical portion of the temperature adjustment core 21 and is injected into the preforms 1. The injected compressed air passes between the periphery of the cylindrical portion and the inner surface of the preform 1, or passes through the temperature adjustment rod 21a to be discharged from the connection portion 21c to the outside via a tube or the like. Thereby, the body portion 2b can be cooled from the inner surface side of the preform 1.

The temperature adjustment tank 22 has a multi-stage structure composed of a plurality of stages (temperature adjustment blocks) aligned in the vertical direction. In the present embodiment, the temperature regulation tank 22 includes a first stage (first temperature regulation block) 22a, a second stage (second temperature regulation block) 22b, and a third stage (third temperature regulation block) 22 c. The first segment 22a includes: a flow path 23 a; a connecting portion 24a that connects the flow path 23a to a mold temperature regulator (temperature regulator) to allow a temperature regulating medium (coolant) of a predetermined temperature to flow into the flow path 23 a; and a connection portion (not shown) that is arranged adjacent to the connection portion 24a and connects the flow path 23a to a temperature regulator to allow coolant to flow out (similar to the connection portion 24 a). The coolant flowing out of the connection portion 24a circulates around the preform 1 in the temperature adjustment tank 22 and flows out of the connection portion (not shown). The second segment 22b includes: a flow path 23 b; a connection portion 24b that connects the flow path 23b to a temperature regulator to allow coolant to flow into the flow path 23 b; and a connection portion 24c that is arranged below the connection portion 24b and connects the flow path 23b to the temperature regulator to allow the coolant to flow out (similar to the connection portion 24 b). The coolant flowing out of the connection portion 24b circulates around the preform 1 in the temperature adjustment tank 22, and flows out of the connection portion 24 c. The third segment 22c includes: a flow path 23 c; a connection portion 24d connecting the flow path 23c to a temperature regulator to allow coolant to flow into the flow path 23 c; and a connection portion 24e that is arranged below the connection portion 24d and connects the flow path 23c to the temperature regulator to allow the coolant to flow out (similar to the connection portion 24 d). The coolant flowing out of the connection portion 24d circulates around the preform 1 in the temperature adjustment tank 22, and flows out of the connection portion 24 e. The temperature adjustment tank 22 is configured to cool (temperature-adjust) the preforms 1 to different temperatures in the up-down direction (longitudinal axis direction, vertical direction), and may include at least two sections of the first section 22a and the second section 22 b.

The compressed air flowing in the preform 1 absorbs the heat of the body portion 2a until it is discharged from the preform 1 and the temperature of the air rises. Thus, the temperature of the air flowing into the preform is generally lower than the temperature of the air flowing out of the preform 1. Therefore, for example, in the case where compressed air flows into the preform 1 from the outside of the temperature adjustment rod 21a and circulates inside the temperature adjustment rod 21a from the tip end of the temperature adjustment rod 21a to flow out to the outside of the temperature adjustment rod 21a, the portion of the body portion 2a adjacent to the neck portion 3 is strongly cooled, so that it may be excessively cooled more than necessary. In contrast, in the case where the compressed air flows into the preform 1 from the tip end of the temperature adjusting rod 21a to flow out from the outside of the temperature adjusting rod 21a to the outside of the preform 1, the portion of the body portion 2a adjacent to the bottom portion 2b is strongly cooled, so that it may be excessively cooled more than necessary. In order to reduce this and cool the preform 1 equally, it is preferable to set the temperature of the section adjacent to the inflow portion of the compressed air higher than the temperature of the section adjacent to the outflow portion. That is, in the case where the compressed air flows into the preform 1 from the outside of the temperature adjustment rod 21a, the temperature of the first stage 22a is set to be higher than that of the third stage 22c, and in the case where the compressed air flows into the preform 1 from the tip of the temperature adjustment rod 21a, the temperature of the third stage 22c is set to be higher than that of the first stage 22 a.

Since the flow paths 23a, 23b, and 23c are formed independently of one another, the sections 22a, 22b, and 22c can each be set to different temperatures by circulating coolant (temperature adjusting medium) of different temperatures in each of the flow paths 23a, 23b, and 23 c. In the present embodiment, it is preferable that the uppermost stage has a multi-stage structure having the highest temperature, and the mold surface temperature of the first stage 22a and the lower stages 22b and 22c as the uppermost stage is set to be lower by 0 ℃ or more and 60 ℃ or less (0 ℃ to 60 ℃) than the glass transition temperature of the material of the preform 1. For example, in the case of using the preform 1 made of PET having a glass transition temperature of approximately equal to or higher than 70 ℃ and equal to or lower than 80 ℃, the mold surface temperature of the second and third sections 22b and 22c is set to 10 ℃ or higher and 80 ℃ or lower, preferably 20 ℃ or higher and 75 ℃ or lower, and more preferably 30 ℃ or higher and 60 ℃ or lower. The mold surface temperature of the first stage 22a as the uppermost stage is preferably set to be higher by 10 ℃ to 20 ℃ than the lower stages 22b and 22 c. Further, the mold surface temperature of each segment 22a, 22b, 22c is preferably adjusted to be inversely proportional to the thickness of the preform 1. For example, in the case where the thickness of the preform 130 made of PET is 1.5mm or more and 3.0mm or less, it is preferable to set the mold surface temperature of each of the stages 22b, 22c to 30 ℃ or more and 80 ℃ or less, and in the case where the thickness of the preform 1 made of PET is 3.0mm or more and 5.0mm or less, it is preferable to set the mold surface temperature of each of the stages 22b, 22c to 10 ℃ or more and 60 ℃ or less.

Since the temperature of the preforms 1 conveyed to the tempering station 20 is too high for blow moulding, the preforms are further cooled in the tempering station 20, whereby the temperature is tempered to a temperature suitable for blow moulding. At this time, since the metal neck mold 50 conveys the preform 1 from the injection molding station 10 while holding the neck portion 3 of the preform 1 and performs temperature adjustment on the preform 1 in the temperature adjustment station 20, the reservoir 2 adjacent to the neck portion 3 may be excessively cooled compared to other portions. However, the temperature adjustment stage 20 sets the mold surface temperature of the first stage 22a, which is the uppermost stage, higher than the mold surface temperatures of the lower stages 22b and 22c, and thus can prevent excessive cooling of the portion of the reservoir 2 adjacent to the neck portion 3. Further, since the mold surface temperature of the lower stages 22b, 22c is low, the portion of the reservoir 2 not adjacent to the neck portion 3 can be reliably cooled. As a result, since the preform 1 is cooled more equally in the longitudinal direction and has a temperature distribution suitable for blow molding, thickness unevenness of the container 1a as a final form can be prevented as a whole.

The preforms 1 temperature-conditioned in the temperature conditioning station 20 are lifted together with the rotating disk while being held on the neck mold 50, and are pulled out from the temperature conditioning pot 22, and are conveyed to the blow molding station 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 station 30 is disposed adjacent to the temperature adjustment station 20, and includes a blow mold 31 and a blow portion (not shown). The blow mold 11 is formed with a flow path (not shown) that is connected to a cooler and through which a low-temperature (e.g., 10 ℃ or higher and 25 ℃ or lower) coolant circulates.

The blow mold 31 has a mold surface on the inner side corresponding to the shape of the container 1a, and is significantly larger than the temperature regulation tank 22 of the temperature regulation stage 20.

The blow-off portion is provided to fill air in the preform 1 inserted in the blow mold 31.

When the preform 1 conveyed to the blow molding station 30 is moved downward together with the rotating disk and inserted into the blow mold 31, the blow member (blow core for blow molding) is connected to the opening of the neck portion 3 of the preform 1, and air is blown from the blow portion into the preform 1, the storage portion 2 of the preform 1 is expanded until the entire outer surface of the storage portion 2 is brought into close contact with and pressed against the mold surface of the blow mold 31 as shown in fig. 1, so that the container 1a is molded.

The preforms 1 blown in the blow station 30 are lifted together with the rotating disc while being held on the neck mold 50, pulled out of the blow mold 31, and conveyed to the take-out station 40 as the rotating disc is further rotated 90 degrees in the counterclockwise direction, as shown in fig. 1.

As shown in fig. 1, the removal station 40 is arranged between the blow-moulding station 30 and the injection-moulding station 10. In the extraction station 40, the neck mold 50 is opened so that the container 1a is no longer held. As a result, the container 1a falls, so that the container 1a is taken out (demolded) from the blow molding apparatus 100.

Hereinafter, a test result of testing whether there is a causal relationship between the mold surface temperature of the temperature regulation tank 22 and the transparency of the container 1a by changing the mold surface temperature of each segment 22a, 22b, 22c of the temperature regulation tank 22 step by step and observing the appearance of the container 1a molded through each step is described.

Here, the mold surface temperature of the temperature regulation tank 22 is set to the following three conditions.

The first condition is that: a first stage: 30 ℃, second stage: 20 ℃, third stage: 20 deg.C

The second condition is that: a first stage: 50 ℃, second stage: 40 ℃, third stage: 40 deg.C

A third condition: a first stage: 70 ℃, second stage: 60 ℃, third stage: 60 deg.C

The molding conditions were as follows.

The molding cycle time was 15.0 seconds. In the injection station, the injection time (filling time) was 9.2 seconds and the cooling time was 1.8 seconds. In the blow station, the cooling agent temperature of the cooler of the blow mold was 15 ℃ and the blow time was 7 seconds. With respect to the preform, the material is PET, weighing about 73g, and the body portion 2b has an average thickness of about 4.2 mm. With respect to the container, the filling capacity was 750 ml. The average draw ratio in the lateral direction was 3.18 and the average draw ratio in the longitudinal direction was 1.37.

As a result, it was confirmed that when the condition was changed from the first condition to the third condition, that is, when the mold surface temperature of the temperature adjustment tank 22 was increased from the low state to the high state, the container 1a was further whitened, and when the container 1a was irradiated with light, the transparency was lowered.

The outer surface temperature of the preform 1 was measured at a time just before the preform was blown under each condition, and the highest temperature of the outer surface temperature of the preform 1 just before the blow molding was compared as follows.

The first condition is that: 73.07 deg.C

The second condition is that: 81.15 deg.C

A third condition: 91.24 deg.C

Depending on the conditions, there is a large difference in the outer surface temperature of the preform 1, and when comparing the outer surface temperature in the first and third conditions, there is a temperature difference of about 20 ℃. In particular, in the first condition, the maximum temperature is only about 73 ℃, which may affect formability during blow molding. Therefore, the full capacity (the amount of water completely filled to the upper end of the neck portion 8) is compared between the first state and the third state. The target fill volume was 888ml, 885.0ml for the first condition and 885.1ml for the third condition. That is, there is little difference with respect to the full capacity. With respect to the shape, there was no problem in observation with the naked eye in the comparative range. Note that the blowing pressure during blowing was 2.0MPa at the second time.

From the above results, it can be seen that when the preform 1 is not cooled as much as in the injection molding station 10 of the present embodiment (when the cooling time after the filling time in the injection molding step is shortened, that is, when the preform is demolded at high temperature), it is also effective to lower the mold surface temperature of the temperature regulation pot 22 in order to prevent crystallization of the preform 1.

The blow molding apparatus 100 of the present embodiment includes the temperature adjustment stage 20 having a multi-stage structure in which the first stage 22a as the uppermost stage has the highest temperature, and the mold surface temperatures of the lower stages 22b and 22c except for the first stage 22 as the uppermost stage are lower than the glass transition temperature of the preform 1 by 10 ℃ or more. Accordingly, since the preform 1 can be prevented from being excessively cooled near the neck portion 3 by the neck portion mold 50, a container with good quality can be manufactured even by the hot parison blow molding method in which the molding cycle time is shortened.

Second embodiment

Fig. 3 is a sectional view of the second segment, fig. 4 is a top view and a bottom view of the second segment, and fig. 5 is a sectional view of the temperature adjustment stage seen from the front. Part (a) in fig. 4 is a top view of the second segment 22d, and part (b) in fig. 4 is a bottom view of the second segment 22 d. Note that in the second embodiment, portions different from those of the first embodiment are described, and the same reference numerals are used to denote substantially the same configurations as those of the first embodiment in the drawings.

In the present embodiment, the second segment 22d is inserted into the temperature adjustment tank 22 and corresponds to the body portion 2a of the preform 1, and as shown in fig. 3, a hollow portion 25 is formed extending in the direction of insertion into the preform 1. As shown in part (a) of fig. 4, the hollow portion 25 is formed by removing a part of the second segment 22d into an arc shape centered on the axis of the second segment 22d, that is, the axis of the temperature adjustment tank 22. The hollow portion 25 is disposed on the inner side (axial side) than the flow path 23 b. The hollow portion 25 is straightly removed along the axial center direction of the temperature adjustment tank 22 so as to penetrate from the upper surface side to the bottom surface side of the second segment 22d, and as shown in part (b) in fig. 4, a hole is formed so as to penetrate in the same arc shape as the upper surface side when the second segment 22d is viewed from the bottom surface side of the temperature adjustment tank 22. Thus, as shown in fig. 5, when the second segment 22d is incorporated into the temperature adjustment tank 22 to adjust the temperature of the preform 1, the portion where the hollow portion 25 that becomes the air layer (heat insulating layer) is formed can be set to a lower temperature than the portion where the hollow portion 25 is not formed. Therefore, when the second segment 22d is rotated about the axial center Z of the preform 1 with respect to the temperature adjustment pot 22, position adjustment is performed so that the high-temperature portion of the preform 1 contacts the portion where the hollow portion 25 is formed, according to the temperature distribution of the preform 1. Thus, adverse temperature inhomogeneities in the circumferential position of the preform can be eliminated.

Third embodiment

Fig. 6 is a sectional view of a half of a temperature regulation stage according to a third embodiment, fig. 7 shows a first section of the temperature regulation stage, fig. 8 shows a second section of the temperature regulation stage, fig. 9 shows a third section of the temperature regulation stage, and fig. 10 shows a fixing plate of the temperature regulation stage.

Part (a) of fig. 7 is a sectional view of the first segment, part (b) of fig. 7 is a bottom view of the first segment, and part (c) of fig. 7 is a partially enlarged view of the bottom view. Part (a) in fig. 8 is a sectional view of the second segment, part (b) in fig. 8 is a bottom view of the second segment, and part (c) in fig. 8 is a partially enlarged view of the bottom view. Part (a) of fig. 9 is a sectional view of the third section, part (b) of fig. 9 is a bottom view of the third section, and part (c) of fig. 9 is a partially enlarged view of the bottom view. Part (a) in fig. 10 is a sectional view of the fixing plate, and part (b) in fig. 10 is a plan view of the fixing plate. Note that in the third embodiment, portions different from those of the first embodiment are described, and the same reference numerals are used to denote substantially the same configurations as those of the first embodiment in the drawings.

As shown in fig. 6, the temperature adjustment stage 20 of the present embodiment includes a first section 71, a second section 72, a third section 73, and a fixing plate 74. The shape of the first, second and third segments 71, 72 and 73 on which a portion of the accommodation surface 70 of the preform 1 is accommodated and the configuration of the fixing plate 74 are different from those of the temperature adjustment stage 20 of the first embodiment.

As shown in part (a) of fig. 7, the first section 71 has a cylindrical shape, and the inner diameter is narrowed at the upper end. The inner periphery of the upper end of the first segment 71 is formed with a part of the accommodation surface 70 for accommodating the preform 1. The lower end of the first stage 71 is formed with a pin hole 71b for positioning with respect to the second stage 72 and a hole 71c for inserting the upper portion of the second stage 72.

As shown in part (b) of fig. 7, the first segment 71 is formed with an enlarged diameter surface 71a such that a part of the diameter of the accommodation surface 70 is increased. The enlarged diameter surface 71a is formed within a range of a substantial angle θ 1 about the axial center O of the substantially circular accommodation surface 70. The pin hole 71b is positioned at the approximate center of the range of the angle θ 1 forming the enlarged diameter surface 71 a.

As shown in the enlarged view of part (c) in fig. 7, the diameter-expanded surface 71a is formed by recessing a part of the inner peripheral surface of the upper end of the first segment 71 forming a part of the accommodation surface 70. The enlarged diameter surface 71a is formed in a range of an angle θ 1 of the diameter equally enlarged by the thickness t1 in the radial direction in the range of the angle θ 1 around the axial center O of the accommodation surface 70. The outer portion of the range of the angle θ 1 gradually decreases in inner diameter and gradually connects to the surface of the non-recessed portion of the accommodation surface 70. The angle θ 1 is in the range of 50 ° to 110 °, preferably 80 ° to 100 °, and more preferably 90 ° around the axis O of the accommodation surface. The thickness t1 is 0.2mm or more and 0.5mm or less, and preferably 0.3 ± 0.1 mm.

As shown in part (a) of fig. 8, the second segment 72 has a narrowed outer diameter at the upper portion thereof, and thus, has a cylindrical shape in which the upper and lower portions have different outer diameters. The inner periphery of the second section 72 is formed with a portion of the receiving surface 70 for receiving the preform 2. The lower end of the second segment 72 is formed with a pin hole 72b for positioning with respect to the third segment 73 and a hole 71c for inserting the upper portion of the third segment 73. In addition, the lower portion of the second stage 72 is formed with a pin hole 72e for positioning with respect to the first stage 71 on a surface formed back-to-back and parallel to the lower end surface where the pin hole 72b is formed. Thus, by matching the positions of the pin holes while inserting the pin 75 (refer to fig. 6) between the pin hole 71b of the first stage 71 and the pin hole 72e of the second stage 72, the circumferential position around the axial center O of the accommodation surface 70 can be fixed with respect to the first stage 71 and the second stage 72.

As shown in part (b) of fig. 8, the second segment 72 is formed with a diameter-enlarged surface 72a such that a part of the receiving surface 70 is increased in diameter. The enlarged diameter surface 72a is formed within a range of a substantial angle θ 2 about the axial center O of the substantially circular accommodation surface 70. The pin hole 72b is positioned at the approximate center of the range of the angle θ 1 forming the enlarged diameter surface 72 a.

As shown in the enlarged view of part (c) in fig. 8, the diameter-expanded surface 72a is formed by recessing a part of the inner peripheral surface of the second section 72 forming a part of the receiving surface 70. The enlarged diameter surface 72a is formed in a range of an angle θ 2 of the diameter equally enlarged by the thickness t2 in the radial direction in the range of the angle θ 2 around the axial center O of the accommodation surface 70. The outer portion of the range of the angle θ 2 gradually decreases in inner diameter and gradually connects to the surface of the non-recessed portion of the receiving surface 70. The angle θ 2 is in the range of 50 ° to 110 °, preferably 80 ° to 100 °, and more preferably 90 ° around the axial center O of the accommodation surface 70. The thickness t2 is 0.2mm or more and 0.5mm or less, and preferably 0.3 mm.

As shown in part (a) of fig. 9, the third section 73 has a narrowed outer diameter at the upper portion, and thus, has a cylindrical shape in which the upper and lower portions have different outer diameters. The inner periphery of the second segment 73 is formed with a portion of the receiving surface 70 for receiving the preform 3. The lower end of the third section 73 is formed with a pin hole 73b for positioning relative to the fixing plate 74 and a hole 73c narrowed inside and configured to communicate with the space in the accommodation surface 70. In addition, the lower portion of the third section 73 is formed with pin holes 73e for positioning with respect to the second section 72 on a surface formed back to back and parallel to the lower end surface where the pin holes 73b are formed. Thus, by matching the positions of the pin holes while inserting the pins 76 (refer to fig. 6) between the pin holes 72b of the second section 72 and the pin holes 73e of the third section 73, the circumferential position around the axial center O of the accommodating surface 70 can be fixed with respect to the second section 72 and the third section 73.

As shown in part (b) of fig. 9, the third section 73 is formed with a diameter-expanding surface 73a such that a part of the diameter of the accommodation surface 70 is increased. The enlarged diameter surface 73a is formed within a range of a substantial angle θ 3 about the axial center O of the substantially circular accommodation surface 70. The pin hole 73b is positioned at the substantially center of the range of the angle θ 3 forming the enlarged diameter surface 73 a.

As shown in the enlarged view of part (c) in fig. 8, the enlarged diameter surface is formed by recessing a part of the inner peripheral surface of the third section 73 forming a part of the receiving surface 70. The enlarged diameter surface 73 is formed in a range of an angle θ 3 of the diameter equally enlarged by the thickness t3 in the radial direction within the range of the angle θ 3 around the axial center O of the accommodation surface 70. The outer portion of the range of the angle θ 3 gradually decreases in inner diameter and gradually connects to the surface of the non-recessed portion of the receiving surface 70. The angle θ 3 is in the range of 50 ° to 110 °, preferably 80 ° to 100 °, and more preferably 90 ° around the axis O of the accommodation surface. The thickness t3 is 0.2mm or more and 0.5mm or less, and preferably 0.3 mm.

As shown in part (a) of fig. 10, the fixing plate 74 has a plate shape of a rectangular section in which an upper surface is cut into a cylindrical shape to form a circular fitting hole 74 a. The fitting hole 74a is formed to have such a size as to fit the outer peripheral surface of the ring member 78 (refer to fig. 6), and the fixing plate 74 is configured such that the third section 73 is attached thereto via the ring member 78. A plurality of pin holes 74b are formed in the bottom surface of the fitting hole 74 a. Thus, by matching the positions of the pin holes while inserting the pins 77 (refer to fig. 6) between the pin holes 73b of the third section 73 and the pin holes 74b of the fixed plate 74, the circumferential position around the axial center O of the accommodation surface 70 can be fixed with respect to the third section 73 and the fixed plate 74.

As shown in part (b) of fig. 10, a plurality of pin holes 74b of the fixing plate 74 are formed at respective angles θ 4 around the axial center O of the substantially circular accommodation surface 70. Specifically, each pin hole 74b is formed at the same distance from the axial center O of the accommodating surface 70 and is positioned to be aligned with the pin hole 73b of the third section 73. The angle θ 4 is in the range of 30 ° to 45 ° around the axial center O of the accommodation surface, and is 45 ° in the present embodiment.

The first, second, and third segments 71, 72, and 73 are adapted to rotate integrally when the positions are determined in the circumferential direction by the pins 75 and 76, and the third segment 73 determines the position with respect to the fixed plate 74 in a state of rotating in the circumferential direction with respect to the fixed plate 74. Thus, the temperature adjustment stage 20 can change the circumferential positions of the expanding surfaces 71a, 72a, and 73a according to the preform 1 to be inserted.

Next, a temperature adjusting step in the temperature adjusting stage 30 of the present embodiment is described.

First, the blow molding apparatus 100 demolds the preform 1 from the injection molding station 10 at a high temperature. At this time, high-temperature portions distributed in a vertically extending direction (i.e., distributed in a vertical stripe pattern) may be generated on a part of the circumferential direction of the body portion 2 of the preform 1.

When the preform 1 is ejected from the injection molding station 10 at a high temperature, the blow molding apparatus 100 conveys the preform 1 to the temperature adjusting station 20.

When the preforms 1 are conveyed to the temperature adjustment stage 20, the blow molding apparatus 100 accommodates the preforms 1 into the cavities defined by the accommodation surfaces 70 of the temperature adjustment tanks 22 such that the high-temperature portions of the preforms 1 distributed in the shape of vertical stripes match the positions of the expanded diameter portions 71a, 72a, and 73 a. Note that, as for the positional relationship between the high-temperature portions of the preforms 1 distributed in the vertical stripe shape and the diameter-enlarged portions 71a, 72a, and 73a, the positions thereof are adjusted in advance in accordance with the result of the test molding of the preforms 1 performed before the molding of the preforms 1 to be intermediate products during actual continuous production. At this time, the position adjustment is performed by changing the position of the pin hole 74b for positioning the third section 73 with respect to the fixed plate 74.

The blow molding apparatus 100 arranges the temperature adjustment rod 21a having the flow rate adjustment member capable of improving the cooling efficiency of the cooling blowing at the neck portion 3 of the preform 1 when the preform 1 is stored in the accommodation surface 70.

In the case of arranging the temperature adjustment rod 21a at the neck portion 3 of the preform 1, the blow molding apparatus 100 performs preliminary blowing by first low-pressure air of, for example, 0.1Mpa or more and 0.4Mpa or less, expands the preform 1, and brings high-temperature portions of the preform 1 distributed in a vertical stripe shape into contact with the surfaces of the expanded diameter portions 71a, 72a, 73 a. At this time, the high-temperature portion distributed in the vertical stripe shape is locally slightly stretched, so that the heat amount thereof is reduced, thereby lowering the temperature as compared with other portions.

In performing the preliminary blowing, the blow molding apparatus 100 introduces second low-pressure air of 0.1Mpa or more and 0.4Mpa or less into the preform 1 by cooling blowing and circulates it, thereby cooling the preform 1 by the air and the temperature adjustment tank 22. At this time, as the flow rate adjusting member inserted into the temperature adjusting rod 21a of the preform 1, it is preferable to use a flow rate adjusting member that cuts in half the portion opposing the high temperature portion of the preform 1 distributed in the vertical stripe shape to form a flow path, because elimination of temperature unevenness is further promoted.

While cooling the preforms 1, the blow molding apparatus 100 extracts the preforms 1 from the temperature adjustment rod 21a, and extracts the preforms 1 from the temperature adjustment tank 22.

When the preforms 1 are pulled out of the temperature-controlled pot 22, the blow molding apparatus 100 conveys the preforms 1, from which the circumferential temperature unevenness is eliminated, to the blow molding station 30.

The temperature adjustment stage 20 of the present embodiment has diameter-enlarged portions 71a, 72a, and 73a formed in the first, second, and third stages 71, 72, and 73, respectively. Thus, the temperature adjustment stage 20 can eliminate circumferential temperature unevenness, i.e., a local high temperature portion of the preform 1.

Fourth embodiment

Fig. 11 is a sectional view of the temperature adjustment stage seen from the front. Note that in the fourth embodiment, portions different from those of the first embodiment are described, and the same reference numerals are used to denote substantially the same configurations as those of the first embodiment in the drawings.

As shown in fig. 11, the first section 22e of the temperature adjustment tank 22 is formed with an annular groove 26 having a rectangular cross section so as to surround the temperature adjustment rod 21 a. The annular grooves 26 are also formed with air layers a, in which air is interposed between the annular grooves 26, thereby functioning as a heat insulating structure. The temperature regulation tank 22 has a heat insulation structure, so that when the temperature is regulated, it can be made difficult to cool the lower portion of the neck portion 3 without setting the first stage 22e to a high temperature, as compared with the first stage 22a of the first embodiment, and also the lower portion of the neck portion 3 can be favorably stretched when the preform 1 is blow-molded in the blow molding station 30. In addition, when the first section 22d is set to a high temperature, similarly to the first embodiment, the temperature of the lower portion of the neck portion 3 can be further suppressed from decreasing while cooling is performed by allowing air to flow in the preform 1. Therefore, the lower portion 10 of the neck 3 can be effectively prevented from being cooled.

Fifth embodiment

Fig. 12 is a sectional view of the temperature adjustment stage seen from the front, and fig. 13 is a plan view and a sectional view of the annular plate. Part (a) in fig. 13 is a top view of the annular plate, and part (b) in fig. 13 is a sectional view of the annular plate. Note that in the fifth embodiment, portions different from those of the first embodiment are described, and the same reference numerals are used to denote substantially the same configurations as those of the first embodiment in the drawings.

In the first stage 22f of the temperature adjustment tank 22 of the present embodiment, as shown in fig. 12, in the annular groove 27, as a heat insulating material, an annular plate 28 made of PEEK (polyetheretherketone) resin is bonded. The bottom surface of the annular groove 27 is a flat surface extending from the bottom portion formed on the inner peripheral surface of the first stage 22f toward the center of the inner peripheral surface.

As shown in part (a) of fig. 13, the annular plate 28 incorporated into the annular groove 27 has a circular ring shape. The annular groove 27 is formed with a plurality of through holes 27a, and screws are screwed into the bottom of the annular groove 27 through the through holes 27a so that the annular plate 28 is fixed to the annular groove 27.

As shown in part (b) in fig. 13, the annular plate 28 has an inner peripheral surface that is inclined such that the diameter of the inner peripheral surface 29 gradually decreases from one end toward the other end along the central axis. Thus, the annular plate 28 is adapted to contact the preform 1 such that the radius of the lower portion of the neck 3 of the preform 1 inserted into the temperature regulation tank 22 decreases in a conical shape toward the bottom end of the preform 1.

The first stage 22f of the temperature regulation tank 22 of the present embodiment also has a heat insulation structure, so that when the temperature is regulated, it is possible to make it difficult to cool the lower portion of the neck portion 3 without setting the first stage 22e to a high temperature, as compared with the first stage 22a of the first embodiment, and also to favorably stretch the lower portion of the neck portion 3 when the preform 1 is blown in the blow molding station 30. In addition, when the first section 22d is set to a high temperature, similarly to the first embodiment, the temperature of the lower portion of the neck portion 3 can be further suppressed from decreasing while cooling is performed by allowing air to flow in the preform 1. Therefore, the lower portion of the neck portion 3 can be effectively prevented from being cooled.

Sixth embodiment

Fig. 14 is a sectional view of a half of the temperature adjustment stage according to the sixth embodiment, seen from the front. Note that in the sixth embodiment, portions different from those of the first embodiment are described, and the same reference numerals are used to denote substantially the same configurations as those of the first embodiment in the drawings.

As shown in fig. 14, the temperature regulation stage 20 of the present embodiment includes a temperature regulation tank body 80 in which the temperature regulation tank 22 is integrally formed, rather than being divided into a plurality of segments as separate members. Specifically, the body portion and the bottom portion of the preform 1 inserted into the temperature regulation can 22 are in contact with the temperature regulation can body 80 on the accommodation surface 70 formed as one surface without a boundary. Note that the temperature adjustment tank body 80 of the present embodiment has a diameter-enlarged surface 72a so that a part of the accommodation surface 70 is enlarged, similarly to the third embodiment.

Although the temperature adjusting tank body 80 is integrally formed, the temperature adjusting tank body 80 has a first groove part 81 and a second groove part 82 at the outside thereof such that it is divided into three regions 83, 84, and 85. Specifically, the temperature-adjusting tank body 80 has three sections (temperature-adjusting blocks) having different temperature settings, similarly to the first embodiment. However, the respective segments are integrally formed, and the first groove portion 81 is formed between a first region 83 corresponding to the first segment and a second region 84 corresponding to the second segment, and the second groove portion 82 is formed between the second region 84 and a third region 85 corresponding to the third segment. Each of the first groove portion 81 and the second groove portion 82 is formed to have a width of 1mm or more and 5mm or less, preferably 1.5mm or more and 2.5mm or less, along the insertion direction of the preform 1, and is air-insulated via air. Thus, the first groove 81 insulates heat between the first region 83 and the second region 84, and the second groove 82 insulates heat between the second region 84 and the third region 85. Note that the first groove portion 81 and the second groove portion 82 may be thermally insulated via PEEK resin.

In the case where the air between the preform 1 and the accommodation surface 70 is difficult to degas (for example, the preform 1 has an elongated shape), the bottom of the second groove portion 82 may be formed with a slit 86, the slit 86 penetrating the accommodation surface so that the space within the accommodation surface 70 is in fluid communication with the second groove portion 82. Thus, the slits 86 function as exhaust ports since the air staying between the outer peripheral surface of the preform 1 and the accommodation surface 70 of the temperature adjustment tank 20 is exhausted, i.e., degassed. Note that it is preferable to provide the slit 86 at a position corresponding to the bottom of the preform 1 so as to make the line formed on the preform 1 as a result of collision of the slit 86 with the preform 1 inconspicuous. The width of the slit is preferably set smaller than the widths of the first groove portion 81 and the second groove portion 82.

Since the multi-stage type temperature-adjusting tank of the related art is divided into a plurality of stages, boundary marks (i.e., separation lines) are always formed on the preform. The separation line may cause poor thickness of the container 1a such as a bottle and poor appearance of the ring line.

The temperature adjustment tank 20 of the present embodiment does not have such a configuration as to be divided into upper and lower separate portions because the temperature adjustment tank body 80 forming the accommodation surface 70 is integrally formed. Therefore, even when the preform 1 is subjected to the temperature adjustment or cooling process, the boundary formed when the accommodation surface 70 is divided is not formed as a separation line on the preform 1.

In addition, the temperature adjustment tank body 80 is divided into three regions 83, 84, and 85, and their boundary portions are thermally insulated by the first groove portion 81 and the second groove portion 82. Thus, a temperature difference may be generated in the fluid flowing through each of the flow path 23a of the first zone 81, the flow path 23b of the second zone 84, and the flow path 23c of the third zone 85, so that a temperature difference may be generated in the up-down direction of the preform 1, or the temperature difference in the up-down direction may be eliminated. Thus, even when the preform 1 is long, the temperature adjustment and cooling in the up-down direction can be favorably performed.

Note that, in the present invention, it is preferable to set the set temperature of an injection cylinder (barrel) of an injection apparatus (not shown) configured to introduce the material of the preform 1 into an injection mold constituted by an injection cavity mold 12 of the injection stage 10 or the like, and the set temperatures of a block portion and a nozzle portion of a Hot Runner (HR) arranged between the injection apparatus and the injection mold to a temperature lower by 5 ℃ to 15 ℃ or more than the molding method of the related art. For example, in the case where the material of the preform 1 is PET, the temperature can be set as shown in table 1. Thus, since it is not necessary to uselessly melt the material (PET) of the preform 1 at a high temperature in the injection molding apparatus, it is possible to mold a high-quality preform 1 in which deterioration of the material is suppressed. In addition, since the preform 1 can be molded at a lower temperature than the molding method of the related art, the cooling time of the preform in the temperature adjustment stage 20 can be shortened.

TABLE 1

In addition, the preform 1 preferably has a different shape from the related art preform. For example, when forming the container 1a having a capacity of about 0.3L to 1L, the thickness of the body portion wall of the storage portion 2 of the preform 1 is set to 2.5mm to 8.0mm, preferably in the range of 3.0 ± 0.8, so that when forming an equivalent container, the body portion wall is made thicker than the related art preform, thereby shortening the length of the body portion. By this method, since the injection space of the injection mold becomes wider than the related art, it is possible to introduce the material under low pressure from the injection device into the injection mold while shortening the injection time (injection cycle time) as compared with the related art. As a result, the preform 1 can be molded into high quality even in a high-cycle blow molding apparatus. On the other hand, according to the related art method of shortening the injection molding time of the preform, the wall of the body portion is generally thinned. However, in this case, the draw ratio (surface ratio) when the container is molded from the preform is lowered, so that the physical properties of the container are lowered. In particular, the physical properties of the container must be sacrificed in order to shorten the injection molding time. In addition, when the body portion wall of the preform is thin, temperature unevenness during injection molding is relatively increased as compared with the case where the body portion wall is thick, so that moldability is lowered. In the present invention, since even a thick preform 1 can be advantageously cooled in the temperature adjustment stage 20, the preform 1 having the above-described shape can be used to shorten the molding cycle and maintain and improve the physical properties of the container.

Further, before the preform 1 whose temperature adjustment (cooling) is completed in the temperature adjustment stage 20 is conveyed to the blow molding stage 30, the preform is preferably made to stand for a predetermined time while being held on the neck mold 50 in a state where the preform is demolded from the temperature adjustment rod 21a and the temperature adjustment pot 22. The predetermined time is set to, for example, 1/3 or less, preferably 1/4 or less of the injection time. The temperature equalization process is further performed on the preform 1 having undergone the temperature adjustment once, so that the temperature unevenness remaining in the preform 1 can be favorably eliminated in a short time. At the same time, the preform 1 can be lowered to a temperature suitable for blow molding. Thus, while blowing defects such as fish eyes (tear pattern), ring patterns (stretch unevenness), and orange peel (surface roughness in the satin state) due to the temperature unevenness of the preform 1 can be reduced, it is possible to improve physical properties and blow the container 1a to higher quality.

Note that when the preform 1 in a high-temperature state is ejected from the injection core mold 11 of the injection table 10, the preform 1 may be deformed into an uncorrectable shape. In order to suppress this, a method of ejecting air from the injection core mold 11 into the preform 1 immediately before the mold release may be employed. Specifically, in the mold closed state of the injection mold, the inner wall of the preform 1 and the outer surface of the injection core mold 11 can be separated/contacted by air. In this configuration, for example, the injection core mold 11 is provided with an annular air slit in a region facing a portion directly below the neck portion 1, and embeds an air circuit communicating with the slit. Thus, deformation of the preform 1 during high-temperature demolding can be reliably prevented.

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 adjusting stage 20 is used in which the preforms 1 are arranged between the temperature adjusting rod 21a and the temperature adjusting pot 22, and air is blown and circulated from the temperature adjusting rod 21a into the preforms 1. However, the present invention is not limited thereto. When the mold surface temperature of the lower stages 22b and 22c other than the first stage 22a is lower than the glass transition temperature of the preform 1 by 10 ℃ or more, a temperature adjusting stage configured to cool the preform 1 while sandwiching and compressively deforming the preform with a temperature adjusting rod and a temperature adjusting pot may also be used.

In the above embodiment, the cooling blowing is performed after the preliminary blowing is performed. However, the preliminary blowing may be performed after the cooling blowing is performed. By performing the preliminary blowing after performing the cooling blowing, the preform 1 that is sufficiently cooled and has the temperature unevenness eliminated can be brought into close contact with the accommodation surface 70 of the temperature adjustment tank 20, and a temperature distribution more suitable for blowing can be given to the preform 1. In particular, in the case of using a multistage temperature adjustment tank, the temperature distribution in the up-down direction of the preform 1 becomes advantageous. In particular, when the eccentric temperature adjustment tanks 20 of the third embodiment are used together, elimination of temperature unevenness of the preform 1 is further promoted, so that a container having favorable thickness distribution can be molded.

List of reference numerals

1: prefabricated part

1 a: container with a lid

2: storage part

2 a: body part

2 b: bottom part

3: neck part

10: injection molding table

11: injection molding core mold

12: injection cavity mold

20: temperature adjusting table (temperature adjusting device)

21: temperature regulated blown core

21 a: temperature adjusting rod

21 b: first connecting part

21 c: second connecting part

22: temperature regulating tank

22 a: first stage (uppermost stage)

22 b: second section

22 c: third stage

22 d: second section

22 e: first stage (uppermost stage)

22 f: first stage (uppermost stage)

23 a: flow path

23 b: flow path

23 c: flow path

24 a: connecting part

24 b: connecting part

24 c: connecting part

24 d: connecting part

24 e: connecting part

25: hollow part

26: annular groove

27: annular groove

28: annular plate

29: inner peripheral surface

30: blow molding table

31: blow mold

40: taking-out table

50: neck mold

50: conveying part

60: ring (C)

70: containing surface

71: first stage

72: second section

73: third stage

73: diameter expanding surface

74: fixing plate

74 a: assembly hole

75: pin

76: pin

77: pin

78: ring component

80: temperature regulation tank body

81: a first groove part

82: the second groove part

83: first region

84: second region

85: a third region

86: narrow slot

100: blow molding machine (resin container manufacturing machine)

A: air layer

O: axial center

Z: axial center